This is no ordinary ping pong ball gun, as “a sheet of drywall was no match for [the ping pong balls], and even particle board failed spectacularly when faced by a 1″ sphere of water.” Video after the break.
You can think of this as a variation on a potato cannon, however his is built to run on compressed air, and it runs on much tighter tolerances.
[via Gizmodo – Tinyenormous]