Scott Hanselman wrote the Babysmash! program in order to protect his computer when his small children banged away at his keyboard. The free program is the Windows equivalent of the Apple program, Alphababy. What the program does is "lock out the Windows Key, as well as Ctrl-Esc and Alt-Tab so your baby can't get out of the application. Pressing ALT-F4 will exit the application and Shift-Ctrl-Alt-O brings up the options dialog."
The alternative is to make the computer off limits to very young children but that would also reduce quality time with your children, especially if you work as much on the computer as Hanselman does. The program is a great way to introduce the computer to toddlers.
Would little children really enjoy this program? You bet. Just check out the Youtube video of this adorable toddler laughing away whilst he experiments with the keyboard. It is a valuable early lesson in cause ( touch a key) and effect (colourful letters and shapes appear).