In addition to a $6,000 prize package, five finalists will get to work with Xbox LIVE Arcade development teams to build playable versions of their game concept, which will be available at the Doritos development Web site www.snackstrongproductions.com.

In late October and early November, visitors to the site will get to play the finalists' games and vote for the one concept they want to see developed for release. The winning concept will be developed by Xbox360 for free download in summer 2008.

The "Unlock Xbox" promotion kicks off today with an online banner campaign on various sites of interest to the younger gaming demographic, a Frito-Lay spokesperson said. Ideas will be accepted through July 29 at the Doritos site.

"Doritos fans continue to tell us how excited they are to be part of, and personalize, what is important to them," says Ann Mukherjee, vice president of marketing for Frito-Lay.

Between Aug. 20 and Nov. 18, visitors to www.snackstrongproductions.com can instantly win Xbox 360 consoles, Xbox Live Gold subscriptions and more.

"We are always looking for new ways to connect with fans and give them unique opportunities for expressing their creativity that only Xbox 360 and our partners can deliver," says Mike Fischer, general manager of U.S. marketing for Xbox 360.

Frito-Lay has made consumer-generated content a cornerstone of its marketing strategy for the Doritos brand. Its "Crash the Super Bowl" campaign drew more than 1,070 videos, with the winner appearing as an ad on the Super Bowl.

Next, the "Fight for the Flavor" campaign let consumers vote on which of two new flavors to put on store shelves, with Smokin' Cheddar Barbeque the winner. The latest "X-13D Flavor Experiment" invited consumers to name a new flavor, and more than 100,000 submissions have come in to date, according to Frito-Lay.