There is a website called Kidswirl.Its kinda for kids though...
meez,hi5,and facebook
i think twitter
Myspace and/or Facebook.
Runescape
orkut.com really it is just like facebook You may also try Bloviated.com. Its like wikianswers, youtube, facebook and myspace put together.
Poptropica and Club Penguin are two.
Twitter,MySpace,Well those are the most popular.
Facebook, Friendster, Bebo, xing, path, hi5, gather.
many many websites get hacked but the most common one for teenagers is myspace facebook and other websites like that
You can go on kidzbop.com! It is like youtube and myspace! But it is just for kids. There is also fbfkids.com (Facebook for Kids) and for little kids there's fbfkiddies.com (Facebook for Kiddies) kidswirl.com also!
In my opinion, well.. There's many other websites. Like twitter, facebook, etc.
Yes Myspace, facebook, Aim and the best is msn messanger