I've recently bought two littleBits modules. The battery connection (blue), and the bright light module (green).
I was staring at them until I came up with this contraption. So, if you`re short on bits then this the "able" for you.
Step 1: Materials
•littleBits (bright light module)
•assorted rubber bands
•battery pack (5v.)
Step 2: The Body
Step 3: Use Your Bits
Step 4: Saran Wrap
Place your Saran wrap over your bright light module and rubberband it around the tube.