In areas with high concentrations of actors, dancers, and other performers, headshots are the bread and butter for many photographers. You can easily create a professional-looking studio portrait like the one shown here with minimal lighting. For this quick example, I placed a Canon 580 EX II on a stand high and to the camera-left rear of the subject, zoomed at 105mm and aimed down directly at her head. The flash's power was set to 1/32.
The main light was another 580 EX II at the 45/45 position, camera-right, with power set to 1/16, modified with a translucent shoot-through umbrella. The flash units were set to manual and were triggered with PockeWizard Plus II's. Canon 7D, 85mm lens at f/2.8, ISO 100, 1/250 sec.
For more info on creating great lighting with small flash units, see Phil Steele's excellent videos >>