At the end of the party you could simply count the amount of empty beer bottles and thus determining your guests’ lack of sobriety. But that won’t account for the broken one or the ones taken home.
Enter the Beer Tracker Bottle Opener & Counter. Crack open a non-twist off beer with this opener and the built-in counter will add a plus 1 to the accumulated score to the display. I’m not sure if the counter can be “zeroed” for future binge drinking sessions, but one has to assume. I do know that the display shuts off after 15-seconds of inactivity to save power and presumably a small sensor in the opener detects when and if a fresh bottle of brew has been cracked. That all being said, there appears to be a speaker of some sort built-in to the handle, unless those very tiny holes are for grippy purposes.
You can pick up the Beer Tracker Bottle Opener for $5.