pixeljunky:

But I have since picked up a bracket and still get shadows occassionally, plus I don't like how fast it zaps my batteries in the flash.

What equipment are you using?  Flashes can be told to do many things, and many of the default things are not what a new user might expect.  For instance, the default setting in many instances is to expose for the background.  This lowers the shutter speed so that the camera still tries to get the background exposed correctly and adds only enough flash to fill in for the subject in the foreground.  Since your background is exposed properly, you can see it - and the shadows you cast on it.  Another setting sets the shutter speed much faster and uses the flash to expose correctly for the subject, which often leaves the background just plain black.  Black doesn't show shadows and this may be what you want.  You may want to try shooting in shutter priority for this, but I don't know what equipment you are using and how it defaults.  You can read your camera and flash manuals and they will explain this for you.

Also, faster lenses may be an option.  If you are shooting below f/2.0, and the subject is lit very well, you may not need the flash at all... 

pixeljunky:

I have considered Lightsphere and a couple of others, but have been told that the distance between me and contestants would make diffuser worthless.