What's Inside
1. Intel D945GCLF2 mini-ITX board (Atom 330, i945/ich7/gma950)
2. 160GB WD Scorpio 2.5" hard drive (16MB/7200RPM/3.0Gbps)
3. 2GB DDR2/667 (Rendition)
4. 210W ATX Power Supply (apparently, it came from a Dell; probably the one that looks kinda 360-ish) - It's got the 2x10 connector (not 2x12) and the 2x2 one, one molex, 1 sata, and 1 mini-molex(whatever it's called tongue.gif )
5. RF Module from an Xbox 360 (Acts as PW Switch, HDD LED, and Power LED)
6. Power socket from a dead PSU
7. Sata cable from a 360
8. Front USB ports from a 360
Tools Used:
1. Dremel
2. Mount screws
3. Solder/Flux
4. Screwdriver
5. Electrical tape
6. That anti-electric shield from the psu, and some foam from a motherboard box
To Do List:
1. Cooling & shielding
2. Add card reader (or something cool) to former memcard slots
3. Add a reset switch and use it where the sync button was (thanx to will5 @ xboxhacker for the idea)
4. Add an internal Blu-ray drive
My desire to do this project came from wanting to do some sort of custom case for a small-form computer, and luckily I couldn't find a mac mini case
Without further ado, here's the work in progress (please disregard the ugliness of the phone cam; it's all I could take pics with).
Here we have the overhead shot. You can see the PSU along the right side, and the motherboard on the left, with the hard drive mounted upside down on the left side, etc.
Side view, showing the screws that hold the hdd.
A look at the PSU.
A full frontal (well, it's work in progress, so I guess it's only a half frontal, but it *is* essentially naked). The RF module from a real 360 is being used as the power button (not pictured).
The backside. I/O plate is fitting nicely, but there's that gap on the side due to how the chasis is cut for a 360. If you can make out where the power plug goes, you can see I haven't cut the side screwhole off yet (hangs over).
As for the DVD drive, I will be using a laptop drive (as per Ben's suggestion), and it will be Blu-ray.
With the PSU, I've been told that since I've took precautions to make sure the mobo and the psu pcb don't contact, that I don't need to worry about shielding for such a low psu.
I fished out a dead 360 and took the USB ports off the front, and threw them in this. They didn't quite fit, originally, and there was the matter of securing them, too.
I took the shielding off, got the dremel out and trimmed it up a bit, and took the shielding off the ports themselves, and put the header in (upside-down). I then put the port shields through the outside, and secured them to the USB fixture with some wood glue (because I didn't have any other glue
). I found out the hard way that wiring the ports by soldering to the bottomside of the header (where there are pins) wouldn't properly connect the USB ports. Since I didn't want to break what seems to be a nicely secured port, I went through the horribly tedius and arderous task of re-soldering the wires to the points right on the port (which was a female of the dog species to do, because I could barely fit my fingers in such a tight space). 
Nontheless, mission accomplished - my USB ports are working perfectly, and are actually from a 360, which kinda adds to the mod, IMO.
I added a fan from a dead PS2 to help cool it a little, though it seems to run quite cool on it's own, so far. I need to run some more extensive tests before I say one way or the other, tho.
Here's the RF module; wired up. I cut the traces around the LEDs that I'm using, though they still need to be wired the exact way I have them in order to work right. I'm sure I just haven't cut the right trace or something, though.
Has anyone done much with the RF module on a PC? Is there a way I can use the LEDs without wiring directly to them (ie, through the pinout)? I saw on will's post he was using a 360 controller, and it looked wireless (though it was dark, so I might not have seen the cord) - Is there any point to hooking up the USB on the RF Module? What would I do about the 3.3v power, as the USB ports are 5v? Currently, I have the traces to the LEDs cut, but I have another RF module or two lying around...
For the OS, I've decided to make it Leopard(only). My reasoning is that if it were a real 360, and the 360 were hacked, the PPC architecture could theoretically be compatible with OSX (but certainly not Windows). Additionally, it's more unique, given it's now a Hackintosh 360
. Here's the install up and running. I had a USB keyboard from an old imac (first gen, iirc), which kinda adds to the mac-ness of the mod. Has 2 USB ports on it, too, though the system probably won't need them, or be able to power too many more Wish I could get the power button on the keyboard to work, but I don't think I can (unless it was a real mac).