Kegbot Kegerator Project - Monitor keg volume & control access.
http://kegbot.org
"Welcome to Kegbot!
Kegerator monitor and access control.
Kegbot is a free, open-source project to turn your beer kegerator into a computerized drink tracker. With Kegbot and our Arduino firmware, you can:
Monitor exactly how much beer is left in your kegs and track the temperature;
Record the volume of each and every pour;
Set up user accounts to track who is drinking, how much, and all sorts of other nutty statistics;
Use special keys (tokens, RFID tags, barcodes) to authenticate your kegerator users;
Control access to your taps (with special valve hardware) to prevent unauthorized pours;
... and many other crazy things! "