I've been trying out a few two light setups for a small studio portrait. This particular one was shot with a gridded flash on camera left pointed at Michelle's face. It's about head height and a little in front on 1/2 power. Hidden behind her is another flash at 1/32 power set to 24mm zoom pointing up and back onto the white paper from waist level. I quite like this as a dramatic look as opposed to the softer shoot-through umbrella I often use for portraits. On some shots I gelled the background blue, but the look was a very washed out pale blue. The background on this one was given a blue tint in photoshop that affects the shadows as well as the highlights.
The grid for the flash is actually made of plastic straws. They're cut to about an inch and a half and glued into a grid, squashed into a sleeve that holds it directly in front of the flash head. I can't remember where I read about this first, but David Hobby has a few good links up about it.