Beer on Tap

These guys marathon alt and marathon pale have been on tap since, well since I drilled the fridge to install the taps. They must be nearing the end of the keg but without picking up the keg you can't tell how much is left. Gives me an idea for BrewPi 2.1. If I can rig up a weight sensor under each keg and monitor it with the arduino, then BrewPi can tell me how many pints are left. Maybe email me when it's time to brew again....