Talon Beta
Talon aims to bring programming, realtime video gaming, command line, and full desktop computer proficiency to people who have limited or no use of their hands, and vastly improve productivity and wow-factor of anyone who can use a computer.
Voice Control: talk to your computer
Noise Control: click with a back-beat
Eye Tracking: mouse where you look
Python Scripts: customize everything
Via Nicholas Riley:
Talon now has great accuracy to go with its speed, robustness and cross-platform support (Mac/Win/Linux). It is also quietly a great Mac automation tool, including keyboard triggers, a version of appscript and accessibility hooks (example).