My son has been playing Club Penguin. This is a wonderful kids' website that manages to be fun, social, slightly edifying and quite safe.
To find such a nice thing on the internet is a pleasant change from narcissic MyFaceSpaceBook, pretendtobeusefulsoyoullbuymybook.org, madeforadsense.com, teenheatpussy.com, and grumpy blogs like this one. It is a bit of a surprise. It's like finding a scout hall built between a pub and a brothel.