I know there are some solutions out there. Lian Li's gargantuan Xbox360 Modding Case and the prohibitively expensive HeatSync Three Sixty. I was just curious if anyone has seen/performed any other usefull case modifications or replacement. Of course, looking for the quieter, smaller form factor. If you've done a home-brew design, I'd love to see pictures.

I don't remember where I saw it, but you can keep your xbox the same, but replace the fans with silent fans.  If your going to mod it I would say that's probably the best mod to do, I don't know if you could get it much smaller without lots of work.  Google xbox 360 fan kits, I'm sure something will come up.  If you don't like the color you can get different faceplates and stuff too, and they are cheap.  A lot less work than putting it in a different case.

rhdins:

I don't remember where I saw it, but you can keep your xbox the same, but replace the fans with silent fans.

I investigated this a while back.  From the myriad of articles and comments on articles I read, it appears that the consensus is that there is not much to be gained in noise reduction by performing this mod, especially if you already have a jasper 360 model, and now you have voided your warranty and cannot return your XBox 360 for RROD.  I would only do this on an older model XBox 360 that is well out of the warranty period.