Pokemon Channel Unlockable Game
Unlock Movie Projector: To unlock the Movie Projector earn all five episodes of the Pichu Bros. Party Panic.

Skip Segments: Press L or R to skip segments while watching TV.

Complete English and Japanese Pichu Bros. movies: Look in the crates after day six.

Unlock all 3 versions of the 9 Pikachu Nice Cards: Find 101 different Nice Cards

Easy money: If you answer quickly and correctly for the Present Quiz you can get 50 to 200 P.

Free Pokemon Nice cards: Go outside and chat with another Pokemon. When the Pokemon ask a question and you answer correctly, they will give you a Free Nice card.

Pokemon Channel Cheats and Code Data Information
Game Title : Pokemon Channel
Developer : Ambrella
Publisher : Nintendo
Platform : Nintendo GameCube
Genre : Virtual pet, Puzzle, Simulation
Mode : Singleplayer
Release date : JP July 18, 2003, NA December 1, 2003, PAL April 2, 2004

source article from:  Pokemon Channel Cheats GameCube