1. Check in using Foursquare/mobile
2. Check in at https://foursquare.com/mob
2011 US Open badge message: Advantage: you! Congrats on checking in to the US Open- the largest annually attended sporting event in the world. Enjoy 2 weeks of heart-pounding tennis action featuring over 500 players serving up more aces than you can count. Game. Set. Check in!