Of course you have heard about Facebook and Twitter, but have you heard about Digg?
Digg.com is a Social News Network, and although it has been around for 5 years, it has only made the leap to super-social network-stardom-status this year. Digg is basically a “newspaper” that is created together by users from across the globe. It embodies the concept of Web 2.0 quite well.
Check out more info here.