c21_promo_free.jpgGSN, the television game show network, has hooked up with ad-supported mobile games community Cellufun to mobilize GSN’s new show, Catch 21, in partnership with WorldWinner, which hosts a free, online Flash-based version of the game.

Catch 21, which premiered on TV on July 21, is kind of like the child of a pop culture Trivial Pursuit and the classic card game 21.

In addition to the mobile version, the companies are also offering true audience participation for the TV show. Because Catch 21 encourages, and even requires, participation, GSN will leverage the audience by enabling viewer involvement from both the Internet and mobiles.