Ben the Geamecube fan spent a month of lonely nights modding his Gamecube controller, Gamecube, and LCD screen into a portable franken-console of Nintendo delights. This thing cost him around 200 ($370) to build, and weighs 2 kg (4 lbs).
He could have made this completely portable by adding a battery pack, but he decided to cut down on the weight and have it be externally powered. Pretty neat overall, but Ben says he won't make anymore. Maybe if you ask him real nicely, he'll show you how to make one yourself.
Handheld Gamecube [N-Central]