Key Codes
Key Codes 1.0.3 runs natively on both Intel- and PowerPC-based Macs and requires Mac OS X 10.4 or later.
Source
Desktop Curtain
Displaperture
Menu Bar Tint
Open-With Manager
Safari Guardian
Service Scrubber
Key Codes is a little utility that displays the key code, unicode value, and modifier keys state for any key combination you press. If you're a developer, this might be useful to you.