Foursquare is also a game where you earn points every time you check-in, which in turn earns you virtual badges. But you can also earn freebies and coupon offers by checking-in at participating locations. To get these offers you have to become the mayor of a particular location, which means you have checked-in at a location more times than any other foursquare user. The mayor of the Bowery Wine Company in New York, for example, gets their first drink of the night free, while the mayor of San Francisco Symphony-Davies Symphony Hall currently gets fifty percent off tickets for the symphony's January 15 concert and access to the post-concert party. Check out .

You can access foursquare on your mobile phone by downloading the or application, visiting , or via SMS (U.S. only) at 50500. Foursquare says a Blackberry app is in development.

Gowalla

Gowalla is a location-based game similar to foursquare, where you check-in to locations using an iPhone app. The gaming aspect is a little different though, since you participate in a game of virtual geocaching and you don't connect with friends as you do in foursquare.

When you visit a location you'll be presented with a list of virtual goods, called icons, that you can pick up. You can only carry 10 icons at once (although you can archive them for safe keeping), so you may have to drop some of the icons you already have at the new location.