Or for a more permanent solution you could goto http://www.ncsx.com and buy a 4.3mm gamebit they sell. It fits any 1/4" driver tool and does the job nicely.
Also, how do I play games with the cover off? Doesn't the lid have to be closed for the game to play? Please let me know.
The problem with making your own gamebit with the bic pens for the GameCube is tightning the screws back.It is pretty good at unscrewing the bits on the bottom off the GameCube,but lacks the strength when tightning the screws back.The plastic will lose its shape which means rips the shape out of the plastic when tightning the bits back.I agree with Icemonkey the GameBit it is a more stable solution to opening the Cube.To play games with the lid off you just keep the top lid off and put the game where it normally is placed without pressing the lid eject button.The lid doesn't have to be closed to play games,but there is a solution real soon that will make it where the big sized discs will be able to fit inside the Cube.I would probably just wait for that solution instead of keeping the top off.It isn't really safe for the system to leave it exposed like that is why I say that.