Quite possibly the two greatest things in the world -- beer and Arduino -- have been married once again in a hack does them both justice. Accomplished maker and alcohol enthusiast Jeff Karpinski turned a spare Uno and an Ethernet shield into a gadget that automatically checks him in on Untappd. The build is connected to his kegerator through a hall-effect flow sensor that sits in his tap lines. Every time he pulls himself a pint of homebrew, the Aruino makes an API call to the so-called Foursquare for beer nerds, and updates his profile. Obviously, publishing to the site every time the keg is tapped could get messy, so there's an automatic five minute time out to avoid getting repeat hits just for topping off. There's also a button that manually engages the five minute lock out, allowing Jeff to pour his buddies a cold one without claiming the drink for himself on Untappd. And updating is a snap thanks to the simple web server that's integrated. Changing what beer is on tap in the API call is as simple as opening a web browser. Interested in upgrading your own kegerator? Check out the source link for complete instructions and a parts list.