Short for "Pocket Monster," it's the name of the latest franchise from Nintendo in Japan. In cartoon form it first became popular when one episode caused massive seizures in kids all across Japan (and, of course, the Japanese news media, not any smarter than the American media, caused even more damage when they showed the offending clip during the evening news), but American parents seem to have forgotten about that and are willing to spend literally thousands of dollars on trading cards and dolls for their little miscreants.

Editorial: I personally think that Pokémon is the only thing keeping Nintendo alive right now. The N64 hardware got old before its time and never had any real decent games for it, and the only reason Gameboy Color is selling so well is because they reissued a color version of the Pokémon training/trading game for it.

Conspiracy theory: I think that the reason for the seizures was they didn't quite perfect their brainwashing techniques and caused the wrong frequency of alpha waves to manifest. Since then they've found the right triggers to subliminally ingrain foreign thoughts into childrens' minds, causing them to successfuly subvert their parents.