Check this out. Zack Aries managed to take a group shot with 29 people in it. He had an assistant hold a grided speed light over the head of each person, taking their picture in turn. He then put the whole thing together in photoshop. Pretty crazy. I would love to take this guys workshop. (web site in flux)
Pingback: wuTalks » Zack Aries: One Light 28 Exposures