There's a Shiny Pichu event at, as far as I know, all Gamestops in America. I'm actually not sure if it is limited to just America. I may be wrong. Anywho, starting on January 30th and ending on February 14th Gamestop will be giving away Shiny Pichus to everyone that comes in with a version of Pearl, Diamond, or Platinum.
After Heart Gold and Soul Silver come out, the Shiny Pichu can be traded over to the system. And if you take said Shiny Pichu to Ilex Forrest where a Spiky Eared Pichu will join your party. The Spiky Ear Pichu cannot be traded however.
The main difference of the Shiny Pichu is that he has the colors of a normal colored Pikachu. If you don't know the difference, like myself, the body color of yellow is darker, and the cheeks are red instead of pink.
LinkWho's going? I am.