Limbo, the mobile entertainment portal, today announced it has signed a year-long deal with Virgin Mobile USA to provide exclusive mobile programming and SMS ad campaigns for the MVNO's five million U.S. customers.

Under the terms of the new deal, Virgin Mobile USA subscribers can play either Limbo Grab or Limbo Unique via SMS or WAP-based Web browsers for the chance to win prizes, including $1,000 cash, a 42-inch LCD TV or a 2008 convertible Ford Mustang. Official rules for the campaigns with alternative means of entry are available at www.limbo.com/virgin.

Back in February, Limbo announced the results of a highly-suspect internal study that attempted to show the effect its SMS ad campaigns had in the presidential primaries.