I thought this post from Doc Searls today was pretty much dead on:
I think letting small children watch TV is like giving them Quaaludes. I also think kids in their most formative years need to interact with each other, nature, and themselves. They need to read and play and feed their curiousity about the world. They need to use their minds and their bodies to explore the Real World.
Is the Net real too? I don't think anybody loves the Net more than I do; but I don't want my kid doing much more than using it as an educational resource every once in awhile. If you're going to get sucked into an activity, let it be reading a book, shooting baskets or playing an instrument.