I agree with what Steve says. If it turns out the "one light" rule holds then my suggestion, like Steve's, would be a soft box I prefer soft bounce for fill over a reflector but that's a matter of taste. Bead board or foam core is nice. Try something white on one side and black on the other in case you decide negative fill is better.
The lamp-on-the-dslr hotshoe a the key should be a last resort and should have some diffusion. Instead I'd use it as a very low level eyelight only. Let the soft box/bounce do your modelling. And-you've snuck in a second light:)
Mark D'Agostino
http://www.synergeticproductions.com
