where should i place my external flash unit relative to the camera?

[shingfan]

The other day, I had a photographer show me her Fong Lightsphere. She showed me how it worked and what it did, and I was downright amazed at the results. If you have time before the wedding, I would get one of these. Google "Fong Flash" and it's the first thing to come up.

it seems really amazing...have you tried it personally and see the actual result?.....also....by using it....do you require any bouncing off the ceiling or wall?...