Many years ago, I started using Brent Simmons' HotKeyTerminal (http://inessential.com/2004/09/27/hotkeyterminal). This allows you to launch or bring to the front the Terminal app on Mac OS X with a simple Command-Escape key combo.
I found this very useful and, after a time, it became indispensable. The original utility, however, has languished and needed updating.
This is my version of HotKeyTerminal, using modern APIs and compiled for the modern OS.
If you don't like the Command-Escape combo, it's trivial to change this to a key combo that works for you.