Here is my second case mod, it is the most basic design, a box with a lighted window to see the inside. To help keep it small the Blu-Ray drive and hard drive would be excluded in the case but would be external and hook up through the usb ports. Instead of using a regular psu the picoPSU (or simular) would be used to help save space.The dimensions of such a case would only be about 7in by 7in (not sure about the height, but a little taller than the motherboard). USB ports could be added to the front of the case for more accessibility. The case fan could be placed on either side (which ever would cool the cpu better) and so could the power jack. This is a very practical design that would be simple and cheap to build.
Here is a view of the front:
Here is a view of the back:
Here is a picture of the power supply: