This is fan for you or your computer that runs off any avalable USB port. I reccomend it for beginners into electronics, right up to the pro's.
It is easy and fun, you can make in literally five minites!!!
REALLY FAST AND EASY!!!
Step 1: Parts and Stuff
1 3-9v motor with blades (out of mini fan) (pictured below (without blades)
1 USB cable (can be ANY of the three types shown below, as long as it has the same wire layout
Some (tiny amount) solder
Nescessary tools (wire stripper/cutter, soldering iron, tape)