K.M.
We keep it under 2hrs a day. However, I don't feel too guilty because I let him watch shows that teach him something. PBS has some great ones like Word World. Other shows I like are Mickey (teaches colors, shapes, counting), Dora/Diego (teaches Spanish, colors, and facts about animals). My son is 2 (will be three in March) and can count 1-20, 10-1, knows colors, shapes, can name/say all 26 letters--upper case, lower case, and sounds the letter makes. Also, get some great DVDs. My son loves Leap Frog Letter Sounds. Leap Frog makes great DVDs.