The GameCube is a nice and small unit with a relatively powerful 486 MHz IBM PowerPC processor and 40 MB memory. Optionally a network adaptor can be attached to the bottom of the unit to provide a 10/100 ethernet connection.
By modifying the GameCube you can unleash the potensial power of the system, i.e
To run applications on the GameCube you can either use the "PSO" method which requires the "Phantasy Star Online" game and the "Broadband Adaptor", or you can install a modchip. The first modchip available for the GameCube was the ViperGC chip, released in December 2004.
Game Cube Innards Revealed [gamesx.com]
Panasonic Q review [ntsc-uk.com]
GameCube Development [gcdev.com]
GameCube Component Cable [lik-sang.com]
The definitive Pro-Scan thread [gpforums.co.nz]
How to make a NGC RGB (VGA) Cable [geocities.co.jp]