diff --git a/Solutions/Endjin.Templify.Domain/Contracts/Packager/Tokeniser/IFunctionTokenizer.cs b/Solutions/Endjin.Templify.Domain/Contracts/Packager/Tokeniser/IFunctionTokenizer.cs
new file mode 100644
index 0000000..5043e48
--- /dev/null
+++ b/Solutions/Endjin.Templify.Domain/Contracts/Packager/Tokeniser/IFunctionTokenizer.cs
@@ -0,0 +1,8 @@
+namespace Endjin.Templify.Domain.Contracts.Packager.Tokeniser {
+
+	public interface IFunctionTokenizer {
+
+		string TokenizeContent( string Content );
+
+	}
+}
\ No newline at end of file
diff --git a/Solutions/Endjin.Templify.Domain/Domain/Packager/Tokeniser/DateFunctionTokenizer.cs b/Solutions/Endjin.Templify.Domain/Domain/Packager/Tokeniser/DateFunctionTokenizer.cs
new file mode 100644
index 0000000..e1070e6
--- /dev/null
+++ b/Solutions/Endjin.Templify.Domain/Domain/Packager/Tokeniser/DateFunctionTokenizer.cs
@@ -0,0 +1,55 @@
+namespace Endjin.Templify.Domain.Domain.Packager.Tokeniser {
+	using System;
+	using System.ComponentModel.Composition;
+	using System.Text.RegularExpressions;
+	using Endjin.Templify.Domain.Contracts.Packager.Tokeniser;
+
+	[Export( typeof(IFunctionTokenizer) )]
+	public class DateFunctionTokenizer : IFunctionTokenizer {
+		private readonly IDateTimeNowFactory dateTimeNowFactory;
+		private readonly Regex dateRegex;
+
+		[ImportingConstructor]
+		public DateFunctionTokenizer( IDateTimeNowFactory DateTimeNowFactory ) {
+			if ( DateTimeNowFactory == null ) {
+				throw new ArgumentNullException( "DateTimeNowFactory" );
+			}
+			this.dateTimeNowFactory = DateTimeNowFactory;
+			this.dateRegex = new Regex( @"__DATE\(([^)]*)\)__", RegexOptions.Compiled );
+		}
+
+		public string TokenizeContent( string Content ) {
+			string results = Content;
+			if ( !string.IsNullOrWhiteSpace( Content ) ) {
+				results = dateRegex.Replace(
+					Content, match => {
+						string format = "";
+						if ( match.Groups.Count > 1 ) {
+							format = match.Groups[1].Value;
+						}
+						if ( string.IsNullOrWhiteSpace( format ) ) {
+							format = "d"; // Short date
+						}
+						return this.dateTimeNowFactory.Now().ToString( format );
+					}
+					);
+			}
+			return results;
+		}
+
+	}
+
+	// For testability:
+
+	public interface IDateTimeNowFactory {
+		DateTime Now();
+	}
+
+	[Export( typeof(IDateTimeNowFactory) )]
+	public class DateTimeNowFactory : IDateTimeNowFactory {
+		public DateTime Now() {
+			return DateTime.Now;
+		}
+	}
+
+}
\ No newline at end of file
diff --git a/Solutions/Endjin.Templify.Domain/Domain/Packager/Tokeniser/GuidFunctionTokenizer.cs b/Solutions/Endjin.Templify.Domain/Domain/Packager/Tokeniser/GuidFunctionTokenizer.cs
new file mode 100644
index 0000000..9f1b05d
--- /dev/null
+++ b/Solutions/Endjin.Templify.Domain/Domain/Packager/Tokeniser/GuidFunctionTokenizer.cs
@@ -0,0 +1,53 @@
+namespace Endjin.Templify.Domain.Domain.Packager.Tokeniser {
+	using System;
+	using System.ComponentModel.Composition;
+	using System.Text.RegularExpressions;
+	using Endjin.Templify.Domain.Contracts.Packager.Tokeniser;
+
+	[Export( typeof(IFunctionTokenizer) )]
+	public class GuidFunctionTokenizer : IFunctionTokenizer {
+		private readonly IGuidFactory guidFactory;
+		private readonly Regex guidRegex;
+
+		[ImportingConstructor]
+		public GuidFunctionTokenizer( IGuidFactory GuidFactory ) {
+			if ( GuidFactory == null ) {
+				throw new ArgumentNullException( "GuidFactory" );
+			}
+			this.guidFactory = GuidFactory;
+			this.guidRegex = new Regex( @"__GUID\(([A-Za-z]?)\)__", RegexOptions.Compiled );
+		}
+
+		public string TokenizeContent( string Content ) {
+			string results = Content;
+			if ( !string.IsNullOrWhiteSpace( Content ) ) {
+				results = guidRegex.Replace(
+					Content, match => {
+						string format = "";
+						if ( match.Groups.Count > 1 ) {
+							format = match.Groups[1].Value;
+						}
+						Guid guid = this.guidFactory.NewGuid();
+						return guid.ToString( format ); // Valid format values: http://msdn.microsoft.com/en-us/library/97af8hh4.aspx
+					}
+					);
+			}
+			return results;
+		}
+
+	}
+
+	// For testability:
+
+	public interface IGuidFactory {
+		Guid NewGuid();
+	}
+
+	[Export( typeof(IGuidFactory) )]
+	public class GuidFactory : IGuidFactory {
+		public Guid NewGuid() {
+			return Guid.NewGuid();
+		}
+	}
+
+}
\ No newline at end of file
diff --git a/Solutions/Endjin.Templify.Domain/Domain/Packager/Tokeniser/TemplateTokeniser.cs b/Solutions/Endjin.Templify.Domain/Domain/Packager/Tokeniser/TemplateTokeniser.cs
index fdf2b66..2f90672 100644
--- a/Solutions/Endjin.Templify.Domain/Domain/Packager/Tokeniser/TemplateTokeniser.cs
+++ b/Solutions/Endjin.Templify.Domain/Domain/Packager/Tokeniser/TemplateTokeniser.cs
@@ -16,13 +16,15 @@ namespace Endjin.Templify.Domain.Domain.Packager.Tokeniser
     public class TemplateTokeniser : ITemplateTokeniser
     {
         private readonly IFileContentProcessor fileContentProcessor;
+        private readonly IEnumerable<IFunctionTokenizer> functionTokenizers;
         private readonly IRenameFileProcessor renameFileProcessor;
 
         [ImportingConstructor]
-        public TemplateTokeniser(IRenameFileProcessor renameFileProcessor, IFileContentProcessor fileContentProcessor)
+		public TemplateTokeniser(IRenameFileProcessor renameFileProcessor, IFileContentProcessor fileContentProcessor, [ImportMany] IEnumerable<IFunctionTokenizer> FunctionTokenizers)
         {
             this.renameFileProcessor = renameFileProcessor;
             this.fileContentProcessor = fileContentProcessor;
+            this.functionTokenizers = FunctionTokenizers;
         }
 
         public void TokeniseDirectoryAndFilePaths(string file, Dictionary<string, string> tokens)
@@ -38,9 +40,13 @@ public void TokeniseFileContent(string file, Dictionary<string, string> tokens)
             this.fileContentProcessor.WriteContents(file, contents);
         }
 
-        private static string Replace(Dictionary<string, string> tokens, string value)
+		private string Replace(Dictionary<string, string> tokens, string value)
         {
-            return tokens.Aggregate(value, (current, token) => Regex.Replace(current, token.Key, match => token.Value));
+            string val = tokens.Aggregate(value, (current, token) => Regex.Replace(current, token.Key, match => token.Value));
+            if ( this.functionTokenizers != null ) {
+                val = this.functionTokenizers.Aggregate(val, (current, tokenizer) => tokenizer.TokenizeContent(current));
+            }
+            return val;
         }
     }
 }
\ No newline at end of file
diff --git a/Solutions/Endjin.Templify.Domain/Endjin.Templify.Domain.csproj b/Solutions/Endjin.Templify.Domain/Endjin.Templify.Domain.csproj
index acf3c62..c87edac 100644
--- a/Solutions/Endjin.Templify.Domain/Endjin.Templify.Domain.csproj
+++ b/Solutions/Endjin.Templify.Domain/Endjin.Templify.Domain.csproj
@@ -67,6 +67,7 @@
     <Compile Include="Contracts\Packager\Processors\IRenameFileProcessor.cs" />
     <Compile Include="Contracts\Packager\Specifications\IFileExclusionsSpecification.cs" />
     <Compile Include="Contracts\Packager\Tokeniser\IEnvironmentalTokenResolver.cs" />
+    <Compile Include="Contracts\Packager\Tokeniser\IFunctionTokenizer.cs" />
     <Compile Include="Contracts\Packager\Tokeniser\ITemplateTokeniser.cs" />
     <Compile Include="Contracts\Packager\Tokeniser\IReservedTokenResolver.cs" />
     <Compile Include="Contracts\Packages\IPackageFactory.cs" />
@@ -93,7 +94,9 @@
     <Compile Include="Domain\Packager\Processors\PackageProcessor.cs" />
     <Compile Include="Domain\Packager\Processors\RenameFileProcessor.cs" />
     <Compile Include="Domain\Packager\Specifications\FileExclusionSpecification.cs" />
+    <Compile Include="Domain\Packager\Tokeniser\DateFunctionTokenizer.cs" />
     <Compile Include="Domain\Packager\Tokeniser\EnvironmentalTokenResolver.cs" />
+    <Compile Include="Domain\Packager\Tokeniser\GuidFunctionTokenizer.cs" />
     <Compile Include="Domain\Packager\Tokeniser\PackageTokeniser.cs" />
     <Compile Include="Domain\Packager\Tokeniser\TemplateTokeniser.cs" />
     <Compile Include="Domain\Packager\Tokeniser\ReservedTokenResolver.cs" />
diff --git a/Solutions/Endjin.Templify.Specifications/Domain/Packager/Tokeniser/DateFunctionTokenizerSpecs.cs b/Solutions/Endjin.Templify.Specifications/Domain/Packager/Tokeniser/DateFunctionTokenizerSpecs.cs
new file mode 100644
index 0000000..df4e61a
--- /dev/null
+++ b/Solutions/Endjin.Templify.Specifications/Domain/Packager/Tokeniser/DateFunctionTokenizerSpecs.cs
@@ -0,0 +1,75 @@
+namespace Endjin.Templify.Specifications.Domain.Packager.Tokeniser {
+	using System;
+	using Endjin.Templify.Domain.Domain.Packager.Tokeniser;
+	using NUnit.Framework;
+
+	[TestFixture]
+	public class DateFunctionTokenizerSpecs {
+
+		private static readonly DateTime testDate = new DateTime( 2000, 5, 12, 2, 52, 19 ); // FRAGILE: Tests hard-code this in expected results
+
+		[TestCase( "", "" )]
+		[TestCase( (string)null, (string)null )]
+		[TestCase( "__DATE()__", "5/12/2000" )]
+		[TestCase( "abc__DATE()__def", "abc5/12/2000def" )]
+		[TestCase( "abc__DATE(__def", "abc__DATE(__def" )]
+		[TestCase( "abc__DATE()__def__DATE()__ghi", "abc5/12/2000def5/12/2000ghi" )]
+		[TestCase( "abc\n__DATE()__\ndef\n__DATE()__\nghi", "abc\n5/12/2000\ndef\n5/12/2000\nghi" )]
+		public void ReplacementExpressions_Work( string Content, string Expected ) {
+
+			// Arrange
+			MockDateTimeNowFactory mock = new MockDateTimeNowFactory( testDate );
+			DateFunctionTokenizer d = new DateFunctionTokenizer( mock );
+
+			// Act
+			string actual = d.TokenizeContent( Content );
+
+			// Assert
+			Assert.That( actual, Is.EqualTo( Expected ) );
+
+		}
+
+		[TestCase( "" )]
+		[TestCase( "d" )]
+		[TestCase( "D" )]
+		[TestCase( "t" )]
+		[TestCase( "T" )]
+		[TestCase( "f" )]
+		[TestCase( "F" )]
+		[TestCase( "dd-MM-yyyy hh:mm:ss tt" )]
+		[TestCase( "yyyy" )]
+		[TestCase( "ddd" )]
+		public void Format_Works( string Format ) {
+
+			// Arrange
+			string content = "__DATE(" + Format + ")__";
+			if ( string.IsNullOrEmpty( Format ) ) {
+				Format = "d"; // FRAGILE: Duplicates business logic in class under test
+			}
+			MockDateTimeNowFactory mock = new MockDateTimeNowFactory( testDate );
+			DateFunctionTokenizer d = new DateFunctionTokenizer( mock );
+
+			// Act
+			string actual = d.TokenizeContent( content );
+
+			// Assert
+			string expected = mock.Now().ToString( Format );
+			Assert.That( actual, Is.EqualTo( expected ) );
+		}
+
+
+		public class MockDateTimeNowFactory : IDateTimeNowFactory {
+			private readonly DateTime dateTime;
+
+			public MockDateTimeNowFactory( DateTime DateTime ) {
+				this.dateTime = DateTime;
+			}
+
+			public DateTime Now() {
+				return dateTime;
+			}
+
+		}
+
+	}
+}
\ No newline at end of file
diff --git a/Solutions/Endjin.Templify.Specifications/Domain/Packager/Tokeniser/GuidFunctionTokenizerSpecs.cs b/Solutions/Endjin.Templify.Specifications/Domain/Packager/Tokeniser/GuidFunctionTokenizerSpecs.cs
new file mode 100644
index 0000000..c58ee7e
--- /dev/null
+++ b/Solutions/Endjin.Templify.Specifications/Domain/Packager/Tokeniser/GuidFunctionTokenizerSpecs.cs
@@ -0,0 +1,102 @@
+namespace Endjin.Templify.Specifications.Domain.Packager.Tokeniser {
+	using System;
+	using System.Collections.Generic;
+	using Endjin.Templify.Domain.Domain.Packager.Tokeniser;
+	using NUnit.Framework;
+
+	[TestFixture]
+	public class GuidFunctionTokenizerSpecs {
+
+		[TestCase( "", "" )]
+		[TestCase( (string)null, (string)null )]
+		[TestCase( "__GUID()__", "00000000-0000-0000-0000-000000000000" )]
+		[TestCase( "abc__GUID()__def", "abc00000000-0000-0000-0000-000000000000def" )]
+		[TestCase( "abc__GUID(__def", "abc__GUID(__def" )]
+		[TestCase( "abc__GUID()__def__GUID()__ghi", "abc00000000-0000-0000-0000-000000000000def00000000-0000-0000-0000-000000000000ghi" )]
+		[TestCase( "abc\n__GUID()__\ndef\n__GUID()__\nghi", "abc\n00000000-0000-0000-0000-000000000000\ndef\n00000000-0000-0000-0000-000000000000\nghi" )]
+		public void ReplacementExpressions_Work( string Content, string Expected ) {
+
+			// Arrange
+			MockGuidFactory mock = new MockGuidFactory( Guid.Empty );
+			GuidFunctionTokenizer g = new GuidFunctionTokenizer( mock );
+
+			// Act
+			string actual = g.TokenizeContent( Content );
+
+			// Assert
+			Assert.That( actual, Is.EqualTo( Expected ) );
+		}
+
+		[Test]
+		public void EachTokenGetsUniqueGuid() {
+
+			// Arrange
+			List<Guid> guids = new List<Guid>() {
+				Guid.NewGuid(),
+				Guid.NewGuid(),
+				Guid.NewGuid()
+			};
+			string content = "__GUID()__ __GUID()__ __GUID()__";
+			string expected = string.Format( "{0} {1} {2}", guids[0], guids[1], guids[2] );
+			MockGuidListFactory mock = new MockGuidListFactory( guids );
+			GuidFunctionTokenizer g = new GuidFunctionTokenizer( mock );
+
+			// Act
+			string actual = g.TokenizeContent( content );
+
+			// Assert
+			Assert.That( actual, Is.EqualTo( expected ) );
+		}
+
+		[TestCase(  "" )]
+		[TestCase( "N" )]
+		[TestCase( "D" )]
+		[TestCase( "B" )]
+		[TestCase( "P" )]
+		[TestCase( "X" )]
+		public void Format_Works( string Format ) {
+
+			// Arrange
+			string content = "__GUID(" + Format + ")__";
+			MockGuidFactory mock = new MockGuidFactory( Guid.NewGuid() );
+			GuidFunctionTokenizer g = new GuidFunctionTokenizer( mock );
+
+			// Act
+			string actual = g.TokenizeContent( content );
+
+			// Assert
+			string expected = mock.NewGuid().ToString( Format );
+			Assert.That( actual, Is.EqualTo( expected ) );
+		}
+
+
+		public class MockGuidFactory : IGuidFactory {
+			private readonly Guid guid;
+
+			public MockGuidFactory( Guid Guid ) {
+				this.guid = Guid;
+			}
+
+			public Guid NewGuid() {
+				return guid;
+			}
+		}
+
+		public class MockGuidListFactory : IGuidFactory {
+			private readonly List<Guid> guids;
+			private int step = -1;
+
+			public MockGuidListFactory( List<Guid> Guids ) {
+				this.guids = Guids;
+			}
+
+			public Guid NewGuid() {
+				// The next one
+				step++;
+				Guid g = guids.Count > step ? guids[step] : Guid.Empty;
+				return g;
+			}
+		}
+
+	}
+}
\ No newline at end of file
diff --git a/Solutions/Endjin.Templify.Specifications/Endjin.Templify.Specifications.csproj b/Solutions/Endjin.Templify.Specifications/Endjin.Templify.Specifications.csproj
index bb1d9ea..477656f 100644
--- a/Solutions/Endjin.Templify.Specifications/Endjin.Templify.Specifications.csproj
+++ b/Solutions/Endjin.Templify.Specifications/Endjin.Templify.Specifications.csproj
@@ -66,7 +66,6 @@
       <Name>Endjin.Templify.Domain</Name>
     </ProjectReference>
   </ItemGroup>
-  <ItemGroup />
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.