Foursquare, Gowalla, Loopt, Scvngr; the list of geolocation based social networks is growing faster than a bodybuilder on steroids.

The idea behind all of these networks is essentially the same: go someplace, do something (a check-in) and get rewarded with a badge, bonus, discount or freebie for doing it. The various levels to be achieved are a big part of the social gaming, in and of itself despite the offerings. Titles like “Mayor” and “Duke” give a clear sense of accomplishment vs. friends and other “competitors.” But there are clear rewards for the companies savvy enough to engage in the game – or, clearly, they wouldn’t be quite as keen to play along.