On Saturdays and Sundays through March 31, 2012, Chipotle restaurants are offering Foursquare users a FREE order of chips and salsa for a limited time. To get this deal, checkin to a Chipotle restaurant on Foursquare to reveal the coupon and show it to the cashier. Participating Chipotle restaurant will be marked with a “SPECIAL” banner on Foursquare.