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)
Step 2: The Building
First, cut the cable at the non-male end( its usually square or smll). Then strip the USB cable and solder thee RED and BLACK wires to their respective contacts on the motor (experiment to see which way makes the prop will push the air FORWARD)
If you're adding a switch, you might need to solder some extra wire depending on where you want it to go, but I didnt 'cause its more practical to use the plug as a switch).
Then Isolate the ramaining wires, tape it up and you're ready to go!