This had me thinking. It my apartment in Boston, I have a projector, but I feared hooking my Wii up to it because of the length I'd need to have in the cable to put the bar right under the image. Then, I thought, maybe I can make one.
So, I did.
With just a perf board, some wires, a bit of soldering, 4 AA batteries, and 4 IR LEDs, I was able to make this:

Yes, it's ugly. Yes, it's ghetto. But, it is a wireless, battery-powered Wii Sensor Bar. And it works. I discussed this not long ago, well someones already done it. I was gonna disassemble a sensor bar and make it wireless, this guy has made it from parts from a shop.
What i wanted to do was run the batteries in the hollow center of the sensor bar so it looked the same, just wireless.