Are you using it for education? If so, can the touch screen honestly provide something the child can't get from the "hands-on world"? Or do you just want a break? Remember that a little boredom can help toddlers learn to entertain themselves.

Melanie Stetson Freeman/The Christian Science Monitor
Kristen Chase, reviews kids touchscreen applications at coolmomtech.com, plays games on an iPad with her four children, Drew, Margot, Bridget and Quinlan.