Attached Link: http://leppphoto.com/Project-A-Flash/

I saw a guy using fill flash for nature shots once. He had a normal flash (a Vivitar 285HV I think) but he had mounted a fresnel lens to it. This concentrated the flash and allowed him to do fill at longer distances. I -think- the link above is the one he was using. Trying hard to remember if this is the one he said. -=>Donald