Here is the best
Club Penguin
Yes It was free chat but teens and younger kids were cusing...yes you can still chat but it is safe!
weeworld.com moviestarplanet club penguin
There are plenty on the net. Simply go to Google and type in your keywords "free chat rooms for kids" and you will come across plenty of good sites. I would personally recommend chat-buddy or teensay which you will find in the Google suggestions.
Skype
4leaf.tk is the best social network ever just for kids. You can create a blog, enter contests, chat in chat rooms, comment on profiles, have your avatar, and more
Franktown rocks is the best messenger for kids ratings for 5
the best kids games would probably be funbrain and for chat rooms and fun thing toontown
I think the best is kidswirl.com.....they allow kids to chat with their friends in a format similar to facebook. Kids can only chat and interact with the friends they have accepted....it is a great option for kids! you could find chatting for kids at weeworld.com and club penguin!! so kids get your butts up and start playin some games!!!
iddin is great
Clubpenguin (see the related link below). Safe for kids and you can dress up and stuff.