Alguma aqui são as redes sociais,se você quiser só clicar no link e se cadastrar

Facebook:

https://www.facebook.com/

Orkut:

https://www.google.com/accounts/NewAccount?continue=http%3A%2F%2Fwww.google.com.br%2F&hl=pt-BR

Hotmail:

https://accountservices.passport.net/reg.srf?id=2&sl=1&lc=1046

My Space:

https://br.myspace.com/

Twitter:

https://twitter.com/

Digg:

https://www.funimation.com/drop

Yahoo:

https://na.edit.yahoo.com/registration?.pd=&intl=br&origIntl=&done=&src=&last=&partner=yahoo_default&domain=&yahooid=

Bebo:

https://www.bebo.com/

Ai vão algumas redes sociais!