A little Usb mobile radar thingy I made from scrap parts, it can be powered on usb (500ma) on any computer. The motor and usb connector were saved from a dead all-in-one printer. The radar dish from a old mac computer and the transmitter from a microwave oven. Everthing else is custom made.
Now we can keep a eye out for ufo's and such...
Got a new "transmitter unit" this time from a old spotlight being thrown away... Cleaned it up and it was perfect for replacement for the old dangerous microwave unit.