Just in time for today’s celebration of Foursquare Day, Christopher McKirgan created The Foursquare Clock, a servo-driven clock that uses the Foursquare API to let his roommates know where he is and how long ago he checked in there. He created a clock face that includes icons for his most visited locations and an indicator for for how many hours ago he checked in. At the core of the project is an Ethernet-connected Arduino, which controls the servos inside an old fashioned wooden clock that he found on eBay. Thanks for sharing Christopher, and Happy Foursquare Day! [via Twitter]