Rihanna returns to the top of the Social 50 chart after abdicating the No. 1 spot to the Black Eyed Peas (1-4) the past two weeks. This is her second week atop the list, having topped it upon its premiere last month.

Latin superstar Don Omar makes a significant jump into the runner-up slot (19-2), prompted by the success of his single with Lucenzo, "Danza Kuduro," which is enjoying an eight-week run at No. 1 on Latin Songs. Omar sees views to his MySpace Music page jump by nearly 600%, with MySpace plays up by 200%.

Akon, who has taken part in some high-profile projects of late, enters the top 10 for the first time with a strong 16-7 move. As pr eviously mentioned, he appeared on CBS' "Victoria's Secret Fashion Show" in November and most recently on the Dec. 18 episode of "Saturday Night Live," where he lent his vocal support the latest comedic effort by the Lonely Island, "I Just Had Sex." Throw in his contributions to Michael Jackson's "Hold My Hand" and Dr. Dre's "Kush," which each premiered videos in the past few weeks, and it's no wonder Akon posts an overall 37% jump in activity. Meanwhile, his collaborators also make moves: Michael Jackson is up a slot to No. 9 and Dr. Dre posts the tally's top debut at No. 35.

Recapping the rest of the top 10, Justin Bieber holds at No. 3, while Eminem (4-5) and Lady Gaga (5-6) both slip a spot and Katy Perry (6-8) and Linkin Park (8-10) each fall two places.

Other notable chart moves include a re-entry for Ludacris at No. 17, which is a new peak for him, and a 34-24 jump by Bruno Mars. Both artists occupy spots on the top 10 of the Digital Songs chart, as Luda is featured on
Enrique Iglesias' risqué "Tonight (I'm Lovin' You)," which jumps 12-9 (108,000 downloads) on that list while Mars moves into the No. 1 slot with "Grenade: (212,000).

Debuting at No. 36 is newcomer DJ BL3ND, a "Chucky" mask-wearing electro-house DJ from Los Angeles. BL3ND post gains on all metrics (from page views, plays and friends/fans/followers) on MySpace, YouTube, Facebook and Twitter, according to online measuring service Next Big Sound.