The Holt Head Screw seems to the be the screw of choice for the gameboy. I have had luck getting only one of the screws off with the crappy screw driver, which was thin enough to get into the spot. I am afraid to strip the other screws and I will probably have to go out and spend some money on a decent screw driver to get this out. I love proprietary tamper-proof screws. They get the job done and have succeeded in getting me officially pissed off. I want more than anything to crack open the gameboy and see what I have to work with. As opposed to what I originally thought, I might have less breathing room than I thought with the cartridge area taking up roughly half the thickness of the gameboy and some drastic modifications may have to occur.

I don't really want to change the Gameboy too much from its original (on the outside at least :-) ) but I would like that PC/104 i've been eyeing as a potential candidate for use to fit and work out. If anything more research will bring more answers as where to proceed and opening up the gameboy will provide those answers.

For a second lets show what the GameBoy specs are from under the hood:

CPU
Custom 8-bit Sharp Z80 at 4.194304 MHz (has a slightly different instruction set than a standard Z80, and integrated sound generation)
RAM
8 kByte internal S-RAM
Video RAM
8 kByte internal
ROM
256 kbit, 512 kbit, 1 Mbit, 2 Mbit and 4 Mbit and 8 Mbit cartridges
Sound
4 channel stereo sound. The unit only has one speaker, but headphones provide stereo sound
Display
Reflective LCD 160 x 144 pixels
Screen Size
66 mm (2.6 in) diagonal
Color Palette
4 shades of "gray" (green to black)
Communication
Up to 4 Game Boys can be linked together via serial ports
Power
6 V, 0.7 W (4 AA batteries provide ~35 hours)
Dimensions
90mm(W) x 148mm(H) x 32mm(D)/3.5 x 5.8 x 1.3 (inch)

(Courtesy of Wikipedia)

It will be cool pushing this thing from a 4Mhz Z80 processor to a 300Mhz+ ARM processor. The sound will definitely have to go, and with a little research, the power source will come into question (6V might be enough but I am not an EE to really know).