These guys over at Yelp.com crack me up, they just built this awesome DIY iPad-controlled beer keg that keeps track of everyone who drank beer and also lets each Yelper to rate the beer.
To use, you will need an RFID card that will allow you to drink the beer. That’s not all though, there’s also a desktop module that let you check the status of the keg (yup, so they never go dry).
Really a cool project they did here, now everyone should go work at Yelp.
Sensors attached to the keg feed data into an Arduino microcontroller, which in turn communicates directly with the iPad via a serial connection. The iPad processes that data and displays it in a snazzy manner along with a description of the current brew. An RFID reader attached to the system allows users to ‘swipe in’ to KegMate and keep track of how much beer they’ve had, as well as assign a star rating for the beer currently in the keg (this is Yelp, after all).