Linking Facebook and Twitter to Foursquare
Linking user accounts
To link your Foursquare account to Facebook and Twitter, make sure you are using Foursquare as your user account. Then hover your mouse over your name in the top-right corner of any page on foursquare.com and click on “Settings" from the drop-down menu. Under “Sharing with other networks” click on “Add Facebook” to authenticate your Facebook account with Foursquare:
Thanks for your feedback!