Copied from an LJ community
SocialVibe is a site that works with your social networks (LJ, Myspace, Facebook, etc.). You sign up, pick a brand, put a banner like the one at the bottom of this post on your profile, and simply for being active on the site you are using, you will earn points for prizes (some prizes that I remember that have already been won: a juicy handbag, ipods, itunes gift cards, a samsung tv, vogue magazine subscriptions), and more importantly you will be raising money for charity.
Some of the charities you would be helping out if you sign up and put a banner on your social networking sites: American Diabetes Foundation, the One Laptop for a Child Foundation, the Save Darfur Foundation, the National Breast Cancer Foundation, the NBA Cares Foundation, the Make a Wish Foundation, the Steve Murray Family Fund, The Vision Charity and the Surfrider Foundation.
This is what one of the codes looks like:
Just click on the banner to join :)