Babysmash is a shareware program at kidsdomain.com for infants and toddlers which flashes colors and shapes on your computer screen with each slap of the keyboard. Your actual system is locked and protected, however, by certain keystrokes that they'll have to tell you when the K-I-D is A-S-L-E-E-P.
It's for Mac only; PC users, just open a PowerPoint presentation you've been working on for weeks and set it to slideshow; I'm sure Windows is robust enough to save all your work from harm.
Related: the Baby Keyboard overlay is a toy keyboard which gives nominal protection from flying sippy cups and vomit--and from whatever your kid's putting on the keyboard, too. ba dum bum. It's $60 whopping bucks at One Step Ahead, and it's for PC only. Guess Mac keyboards are already toylike enough. [via boingboing]
The baby keyboard is fine if you're going to use their software or whatever, but if you're just looking for protection then sixty bucks is an awful lot to spend for a spill proof keyboard. I've seen these for sale at the usual superstores.