Double pop that collar, son!
Checkin to locations tagged as "douchebag".
Tip: Do a search on Foursquare for "douchebag". You need 25 checkin at different places tagged douchebag to get this badge.
Update: As Foursquare has gotten more mainstream this badge has gotten harder to get. It hasn't been officially cut off but it has been suggested that you might need 20+ checkins at douchebag locations to unlock. Also this tag has been locked and you can no longer tag locations as douchebag. Learn more.