It's just like regular polo, except the players ride Segways instead of horses. The first organized match was in 2004, and now the game is played worldwide. The international championship tournament is called the Woz Challenge Cup (yes, named after Steve Wozniak) and has been held annually since 2006. Link -via Fuzzytopia
(image credit: Luiza)
YouTube search: Kathy Griffin - My Life On The D-List S4E09 part 3/5
They used to be called Dunk Tanks, unless that's where you go to take a dump - maybe without having to step off your segway.
I saw it at the first Maker Faire a few years ago and wow...NERDS!!!