I talked to rik about this one, unfortunately he is busy..
I'm VERY interested to try this one out, but I will try it out once i gets my car and I will be able to go somewhere i wanted such as electronic stores.
Rik did a nice test for me.
He tried to cut some cds, fortunately they don't crack. Make sure you have the sharp tool to do this. I watched the video, they used the scissor, which it is cool thing.
http://www.youtube.com/watch?v=L79Rj...eature=related
And for the motor, rik recommends 4,000RPM 6V motor, the usb will be operating at 5V, so the fan will be at around 3,000 ~ 3,5000 RPM, just enough to keep you cool and nerder. lol
Anyway, happy building!