[JAM, MDA Compact, S100 General] nvrnuff:
I got my black xda mini housing off ebay for about 40 dollars from some ebay store in China. It looks and feels genuine enough. Works and fits pretty well, although not perfectly. I give it a 9.5 of 10 in terms of how snugly it fits together, whereas the original housing was a 10. Man that original housing was sturdy.

Replacing the housing was a pretty delicate procedure, but not something you can't do if you use a little common sense. Here's a few tips though:

-DO NOT TRY THIS IF YOU HAVE SHAKY HANDS OR BAD EYES

-THIS WILL VOID YOUR WARRANTY

-You'll need a 6 point head screwdriver (like this: * ). My housing came with one.

-You'll also need a very small philips head screwdriver. My leatherman was extremely handy.

-Use the pdf file for disassembling the jam. I think it's linked somewhere in this thread. Even if you can't find it, it's really not that hard. Take the battery cover off (and all cards out, obviously) and start with the top, back piece: the one around the camera and speaker. Begin by prying the bottom right corner of that piece out and away from the body of the device with a very small flathead screwdriver or probe. The rest will follow.

-Have rubbing alcohol, qtips, and a can of compressed air handy. You'll want to clean the inside while you're there, not to mention all the connectors when you're putting things back together.

-Have a clean, flat working space, preferably white with no cracks or places for small screws to hide if you drop them. This thing has some tiny parts. HAVE ENOUGH LIGHT.

-This is gonna sound ludacris, but model glue is handy. The plastic on the inside is soft, and I stripped one or two of the tiny screws. It didn't end up being a problem, but I glued them into their holes anyway.

-Be sure to reconnect everything: the lcd screen (make sure all the contacts meet and the tape connector is alligned correctly in the plug), the buttons (tape connector), the earpiece speaker, the antenna contact that touches the metal part of the housing, the vibrator motor, everything. There's a lot of little pieces and a lot of connections that have to be removed and put back in to place during this process.

-Work very slowly and very carefully. It took me an afternoon to disassemble, clean, replace the housing, reassemble, and then disassemble and reassemble again to check my work. You aren't gonna do this (well) in a half hour. Even then, I stripped two of the tiny screws and the battery cover takes some adjusting to fit right now.

This process is much more involved than you think. But it's really not very hard if you have any common sense (or a pulse). Just don't expect it to be like replacing the $4 plastic cover on your old Nokia. But if your Jam is out of warranty and it's banged up (mine was nearly falling apart), I strongly recommend this repair. And while you're in there, if your LCD is nasty, order a new one off ebay for $100. I didn't, but they're not hard to replace once you've got the device apart anyway (I just applied a boxwave cleartouch antiglare screen protector while I had the LCD out; it's really a great protector and my screen scratches are no longer noticeable).