If you need some cheap and novel ambient lighting for your next party, you're only a box of ping-pong balls and a string of lights away from solving your lighting worries.
Instructables user AdvancedMischief needed some novel lighting and was impressed with the diffusing power of the simple ping-pong ball:
At some point last semester I realised that ping pong balls make great diffusers and look really cool when they are glowing. Next we concluded that a hundred glowing ping pong balls would look even cooler. It was at about this point I decided that my apartment was in dire need of some ping pong ball lights.
You'll need a strand of lights, ping-pong balls—he recommends buying in bulk on eBay, versus paying retail rates for small packages—and a tool to poke holes in the balls. A drill or even a nail will suffice. From there it's just a matter of punching holes in a bunch of pingpong balls and wiggling the light inside. For more details check out the full tutorial at the link below.
Ping-Pong Ball Lights [Instructables]