For a while we couldn't figure out when to know if we were too drunk and it was time for people to go home.
Tonight, however, we finally figured out the Guitar Hero Field Sobriety Test.
If you (or someone else) is worried you are too drunk then you have to play either "One", "Battery" or "Creeping Death" on Guitar Hero Metallica.
If you fail out, then you are too drunk. If you can do any of those three songs to the end then you are fine.
(I should note - nobody is driving. This is just "too drunk for the neighbors.")