The first challenge is already underway, and it's a big one: you can win a $10,000 vacation to anywhere you want if you check into three "summertime locations" (think beaches or movie theaters) no later than June 19th.

It's a relatively small move, but it could do a lot to help Foursquare draw in users who might have drifted away. While it's fun to get bragging rights for a mayorship, part of the allure of the original Foursquare app was getting that discount at the coffee shop you visit every day. If Swarm offers enough perks in the right places, you'll have a good incentive to keep using the app regardless of how competitive your friends might be.