On its own, this is a pretty cool project. Using an Arduino microcontroller together with KegBot software and the Kegbot Arduino firmware, you can track the temperature of your beer and know how much is left, view statistics on who drank what, authenticate users via RFID tags, prevent unauthorized drinking, and more.
But why stop there? Why not add an iPad and let it communicate directly with the Arduino? That way you can give the whole experience an amazing UI. The project was a natural for a few engineers from Yelp; it combines their love of hacking, beer, and iPads.
The video below shows the finished product, which lets users swipe an RFID card for access, pour the beer, rate the beer, view who else has been drinking it, and get other information on sleek-looking screens. Just for kicks, they also made a bookmarklet to let you see from your desk how much beer is left in the keg. (I haven't worked in an office in a long time. Are kegs standard these days?)
They're currently exploring ways to store data about beer and users on an independent back-end so they can support multiple KegMates in different locations. And they've even detailed exactly how to get your own KegMate up and running. Two notes: you may need to jailbreak your iPad to use its serial port for the project, and you should probably not start drinking until after you get your bot up and running.