A power hour is a drinking game where a bunch of people sit around a table with shot glasses and a whole bunch of beer (or something harder if you're really hardcore), and take a shot every minute for an hour, for a total of 60 shots. There's just something about administering dilute alcohol slowly over the course of an hour that makes you extremely drunk, usually after the first half of the game. It's a game in the sense that the goal is to still be taking shots after everyone else has passed out or declared that they're too shnacked to continue. I swear that each minute seems shorter and shorter as the game goes on.

One variation that keeps you from staring at a clock the whole time (and makes the whole hour much more fun) is to have a special CD with 60 tracks each with the first minute of a good drinking song. Every time the music changes, take a shot of beer.