Time for a brew!

With GameCube/Wii SD Media Launcher, you can run all your home brew Cube software on an unmodified GameCube, or on a Nintendo Wii in GameCube Mode.

All you need to do is download the program of your choice from one of the many web pages dedicated to amateur programming on the Cube. Drag and drop it onto your Micro SD card then plug it into your Wii or GameCube. Launch the application CD on your console and the home brew program is run from there.