I just shot the Strobist assignment (5.2: Double Duty Light). The idea was to compose a shot using just one light, off-camera of course. After some false starts, here’s what I came up with.

The key light (OK, only light) was a Canon 430 EX. It was off to camera left, placed further back of the subject, sort of between the subject and the back wall of the sweep. That sweep, by the way, is a $4.99 piece of gold paper I picked up at Aaron Brothers. I’ve had it for years, and use it all the time. I also have one in silver. They’re really handy.
I put a yellow gel on the background half of the speedlight. That allowed the light hitting the back of the sweep to have a little extra warmth, and the light hitting the subject was allowed to stay white. A mirror placed camera right bounced some of that white light back onto the subject. That’s what’s illuminating the standing quarter.
A piece of foam core to camera right helped fill in some of the background shadows.
Here’s a diagram showing the setup:

If you want to go the easy route to lighting a scene with a single strobe, you can create a light tent or reflector box and fire away. You’ll get a flat even lighting all around the subject. Sometimes that may be exactly what you’re looking for. For this assignment, however, I didn’t want to do that. I wanted instead to create a scene that had the look of multiple lights. One way to do that was to create harsh reflections. I figured that would look more like a second light source, and less like a reflector. Mirrors do a great job of reflecting the light without any diffusion or light loss (if they didn’t do that, they wouldn’t be very useful additions to our bathrooms), so that’s what I used at camera right.
I’ve been looking through the Strobist Flickr pool, and there are some great examples of double/triple/quadruple lighting in there. Nice work, folks.