I guess there are a couple other names for it too...
Heres how it goes:
Flip cup, also known as 
Canoe, is a 
team-based 
drinking game. Effectively a drinking 
relay race, it is similar to the drinking game 
boat race.
The two teams stand on both sides of a table, facing one another (the
person in front of a player is his/her opponent). In front of each
teammate is a cup filled with an arbitrary amount of any kind of liquid
(often 
beer).
A player and his opponent both have the same amount of liquid. At the
start of the race, the first member of each team drinks his or her
beverage. When finished, the cup is placed "mouth up" at the edge of
the table, and the person who drank it tries to 
flip
it upside down, "mouth down", on the table. If he or she is not
successful on the first try, the cup must be reset and re-flipped. Only
after the first teammate is done flipping the cup successfully, can the
next person proceed. Whichever team finishes drinking and flipping all
its cups first is the winner.