I finally bought a used Xbox, ripped it apart, replaced the 10GB drive with a 320GB drive, upgraded that god-awful fan that comes with it, popped/soldered in a mod-chip, replaced the ATA cabling, added an LCD panel with USB ports plus mod-chip push-button controls and loaded up XBMC on it. Now it's basically a home theater PC (HTPC) that also plays Xbox titles. (Yes, the USB ports allow for wireless keyboards, mice, thumb drives and so on.)

Thanks to Warwick for the nudging toward checking out XBMC, which totally p0wns, no questions. I would have never done any of this if it weren't for his regular ramblings and extollings of the open source project that really should just complete its port to the PC.

How did it go? Painfully. Man, I don't care what anyone tells you, modding an Xbox can be a real pain in the rear, among other things.

For example, putting this LCD panel:
http://www.analogduck.com/gallery/v/xbox/DSCN8692.JPG.html

...on this case:
http://www.analogduck.com/gallery/v/xbox/DSCN8695.JPG.html

...resulted in this (photo taken after the initial clean-up):
http://www.analogduck.com/gallery/v/xbox/DSCN8732.JPG.html

By far, the two biggest pains were the front panel disassembly and re-assembly, and the dremelling/grinding/sanding/snipping/chopping of case parts to make everything fit. And there was a lot of that (much more than I revealed in my photo gallery, because taking all the photos would have really slowed the process). Thankfully, making square pegs fit round holes is my specialty:
http://www.analogduck.com/gallery/v/xbox/DSCN8755.JPG.html

Of course, I love it when I do a perfect soldering job exactly as my installation instructions show:
http://www.analogduck.com/gallery/v/xbox/DSCN8768.JPG.html
http://www.analogduck.com/gallery/v/xbox/DSCN8758.JPG.html

...only to find out that they labeled the *wrong* points on the motherboard as places to solder. :P

Thankfully my de-soldering went as smoothly as my soldering, though at one point my back cramp I've been suffering through decided to give me a massive spasm of pain right when I was about to touch the soldering pen to the board. It took all my concentration not to fling the damned thing while my body wrenched in agony, but that's another story.

So, how many components come in an Xbox? Well here's a pic of everything that was and would be:
http://www.analogduck.com/gallery/v/xbox/DSCN8773.JPG.html

Where are all these cables supposed to go anyway?
http://www.analogduck.com/gallery/v/xbox/DSCN8790.JPG.html

Here's the Xbox trial run without the drives:
http://www.analogduck.com/gallery/v/xbox/DSCN8798.JPG.html

With the drives, but no lid:
http://www.analogduck.com/gallery/v/xbox/DSCN8802.JPG.html

The LCD didn't come out well in this lights-out photo (and I'm sure the protective shipping plastic that I didn't bother to remove doesn't help), but you get the idea of how pretty this thing looks now in the dark here. Also you can see my ugly yellow ATA166 cable that I replaced the Xbox ATA133 cable with for a noticeable performance boost:
http://www.analogduck.com/gallery/v/xbox/DSCN8890.JPG.html
http://www.analogduck.com/gallery/v/xbox/DSCN8891small.jpg.html

I found that the RF shielding from the original case was not necessary for RF shielding, but was necessary to prevent grounding problems. There was a large amount of video interference/distortion until I put the shielding into the new case. I used some metal snips to chop out a good deal of the shielding that tended to get in the way of working with or wiring the Xbox. The original configuration is unbelievable painful to try to work inside. My new RF shielding now looks like so:
http://www.analogduck.com/gallery/v/xbox/DSCN8889.JPG.html

The finished product (glowing like this in the sunlight no less!):
http://www.analogduck.com/gallery/v/xbox/DSCN8949.JPG.html
http://www.analogduck.com/gallery/v/xbox/DSCN8939.JPG.html
http://www.analogduck.com/gallery/v/xbox/DSCN8954.JPG.html
http://www.analogduck.com/gallery/v/xbox/DSCN8952.JPG.html
http://www.analogduck.com/gallery/v/xbox/DSCN8955.JPG.html
http://www.analogduck.com/gallery/v/xbox/DSCN8961.JPG.html
http://www.analogduck.com/gallery/v/xbox/DSCN8942small.jpg.html
http://www.analogduck.com/gallery/v/xbox/DSCN8940small.jpg.html

Or, see the whole gallery here:
http://www.analogduck.com/gallery/v/xbox/

I tried a variety of dashboard replacements, but eventually determined that XBMC (Xbox Media Center) is unparalleled.
http://sourceforge.net/projects/xbmc
http://www.xboxmediacenter.com/

The dash essentially looks like this and can launch just about any media file under the sun in addition to launching Xbox executables. See lots of XBMC screen caps here to get an idea of what the dash has to offer.

One of the older skins can be viewed here, though this is not nearly as polished as the current default skin:
http://www.xboxmediacenter.com/info_screens.htm

I can launch files locally (DVDs, CDs, hard drive files- AVIs, MPGs, Real Media, QuickTime movies, etc.), across the LAN from my system shares, FTP, etc., or even the Internet. It plays Shoutcast streams, from RSS feeds, YouTube FLVs, whatever. I've got all my Xbox titles loaded on the hard drive, along with a ton of movies/anime/etc. I have my server shares mapped so I can browse music, movies, pics or whatever from the XBMC. So I haven't had to pop in a single disc since I performed the mods. I have the weather and time servers configured. I've totally tailored the XBMC menu layout and system config to my needs (mostly XML files, in case you're curious), and about the only thing I haven't done yet is configure the Xlink stuff to play online, multiplayer games with the free service.
http://www.teamxlink.co.uk/

Was it worth it all? Definitely. It r0xx0rs. Was it fun? Yes. In a masochistic manner of speaking. However, if I didn't also want an Xbox to play with, I would opt for a PC/Mac based media center solution by far. I hate the Xbox case (cooling is horrible, upgrading it is beyond difficult, and working inside it is less than desirable), and the Xbox components are already getting rare to find, so maintenance is sure to be a pain. I figure on just buying another Xbox and stashing it for spare parts. The power supplies and DVD drives are usually the first to go, and they're already difficult and expensive to find. (The third-party knock-offs are supposedly very shabby.)

I’ve been totally cracked out on a shlew of Nintendo music that is really durn good music. The two albums I must pimp to everyone:

• Legend of Zelda: Ocarina of Time Hyrule Symphony
• Mario & Zelda Big Band Live CD (while you're there, also note the (Mario & Zelda Big Band Live DVD)
  

That these two albums are of exceptional quality is an understatement. The first of the two is symply phenomenal. Top-notch symphonic performance as good as any you would listen to. The second album is just plain fun, my only complaint being that the recording style was to include the live audience instead of isolating the sound of this incredibal band in studio fashion.

When it comes to console games that are on discs, I used to be hesitant to buy them used, as I don't want to shell out a bunch of dinero then find out months later that one of the scratches on the disc causes the game to crash on the final level of the game, or some similar disaster. I buy my games at GameStop these days for several reasons, one of which is that I can bring my used games back to get a full refund for any reason in the first 7 days, even if I just don't like them, and I can exchange for another game anytime within 14 days.

Even if the game I get has a problem that doesn't show up for months, I'm still without worries. For me, all I have to do is drive a mile to Games for Less, where they've got some kind of uber disc repair machine (not necessarily the one I've linked to, but not one of those cheap $20 items you see at Best Buy or CompUSA).