When the red ball was available at recess you were the four square queen but double taps, black jack and clobber have since been traded for iPhone apps, Red Hat and blogger. Ready for a childhood flashback in the new media age? Check out foursquare, the friend-finder, city guide and social media game that combines your love of going out and about with your techie know-how.

foursquare is a mobile application that connects with the social media sites you already use to help you build a profile based around the things you do with your friends and around your city. Use your phone to check in while you’re at your favourite restaurant, on the train, at a museum or see something cool around town. foursquare will update your profile to show how social you are, let you know if any of your friends are nearby, help you find other cool things to do and award you badges and special profile prizes for doing things like staying out late on a school night or visiting places far outside your neighborhood. Check in around town often enough and you might even become the foursquare city “mayor” for your town.

Currently foursquare is only available in a few US cities as well as Amsterdam and Vancouver but you can sign up in anticipation of a trip or foursquare moving to a city near you. The foursquare application is available for iPhones and Android handsets but you can check in from any mobile phone. The founders claim they are pretty much making it up as they go along – also slightly reminiscent of playground game rules – so expect a lot of updates from the service as it grows.

Now stop kidding around and check out foursquare.