Rovio has just announced a new social addition to the Angry Birds universe, "Angry Birds Friends". Available on Facebook, Angry Birds Friends gives new weekly tournaments, new weekly levels, and even more ways to earn power-ups -- plus Share & Play, power-ups, and daily rewards.

Every week, users have from Monday to Sunday to compete with their friends on four different levels. The pig-popper with the best overall score will earn a gold trophy, with silver and bronze for second and third place.

Angry Birds Friends has four new levels exclusively in tournament mode, with new levels coming each week.

In addition to the daily rewards, users can now earn power-ups through tournament mode. Earn three power-ups bundles for a gold trophy, two for silver, and one for bronze. Users also get a power-up for each tournament level they play, and one for participating in the tournament.