Just remember that the Sto-Fen Omnibounce will do very little without a reflective surface. Many people put the Sto-Fen Omnibounce on their flash and leave it there. However, without the reflective surface, you get a very similar light source as you do with a bare flash head.

This plus the fact that it'll suck your flash batteries dry faster than a vampire bat on steroids - your range is cut dramatically and your flash has to put out enormous amounts of energy to expose shots outside.

Use it indoors.