A reader asked this a few weeks ago:
Good question. I think like most things, the answer to this one is moderation. A little bit is good, but more is not necessarily better. I would adhere to the AAP policy of 2 hours of quality screen time a day. So mix and match your Blue’s Clues, Sesame Street, PBSkids.com, Wi and LeapFrog. And then let them run outside, play with their friends and read some books.