A resourceful videographer, Parker Maimbourg, has managed to build a continuous ring light for just $20.
The setup consists of a cheap, circular LED lamp ($10), an AA battery holder ($1.99), and an unused hotshoe salvaged from an old flash unit. A continuous ring light is typically used to provide even illumination for portraits and closeups and usually costs at least a few hundred dollars.
Basically, Maimbourg rewired all the LEDs on the lamp to a separate battery holder, which will be mounted on the camera's hotshoe. Next, he cut a hole through the center of the circular lamp enclosure to fit his lens, spray-painted the whole setup black for that professional feel, and voila!
But before you run off to the nearest hardware store, do note that you'll need some tools like a dremel and a soldering iron, plus a lot of patience to pull this off.