# Every time your computer boots up, PawSense will automatically start up in the background to watch over your computer system.
# Even while you use your other software, PawSense constantly monitors keyboard activity. PawSense analyzes keypress timings and combinations to distinguish cat typing from human typing. PawSense normally recognizes a cat on the keyboard within one or two pawsteps.
# If a cat gets on the keyboard, PawSense makes a sound that annoys cats.
This teaches your cat that getting on the keyboard is bad even if humans aren't watching.
http://www.bitboost.com/pawsense/