Join a team, check in on foursquare, rule the leaderboard, take over the world.
This app lets you and you friends create teams and compete for dominance of your local venues. Its great for inter-departmental wars (who can make the most coffee runs this month?) or for driving lunch business (the company with the most checkins gets a free catered lunch).
Simply log in via the foursquare API and create or join a team. From that point forward, all your foursquare checkins will be afforded to your team. Leader boards are easily accessible for each venue.