Yeah, both my girls use the computer. Both play onine kids games. Nick Jr is great for DD2, DD1 is more paper doll dress up things
I let them chat to my sister & SIL on my MSN, but I'm not even sure I'd let them on fb etc at 13... I really don't know. Its a long way away, but I do feel that 13 is too young. (Depending on the child I guess)
My SIL has bebo & loves it. Its more for the younger ones that I can see. Say 13 up. I'd allow it at maybe 15? I have it, but don't use it coz I think it is too young. There isn't the same crap thrown around that there is on FB, but then you get PM's offering you porn site things.
I'm not keen on any of it, but I know my 7 year old won't be getting her own FB for a loooong time yet!