Edit:
Thanks for the guesses, Hector and Nic specifically. Hector, I did not have a wireless trigger, radio or optical, for my flash. I tried to clarify that by listed everything I used but it wasn’t quite clear evidently. Nic, if I interpreted your guess right this was not taken on the second-curtain sync. This was accomplished by setting up the tripod with a 30 sec exposure (it was pretty dark) with the ten second timer. I focused manually. Then I grabbed my flash which was set at Manual Low and told Dietrich to stand in front of the camera. I stood about 45 degrees off axis of the camera and as soon as the shutter clicked, I fired the flash simply by hitting the “Test” button. Then Dietrich and I traded during the exposure and he fired the flash at me. We took about four more, some with four of us, but none turned out quite as nicely as this one. Anyone can do this. All you need is a camera, tripod, and light source.
I would love to get a bit more interactive with my site as there are a number of capable photographers among my (at least casual) readership.
If anybody happens to get inspired by this I would love to see your work and post it on here if you do something similar. Anybody who wants to get their flash off of the camera should visit Strobist.
I think I’m going to make everybody guess how this was done. I think it should be fairly simple and to make it easier I will tell you exactly what I used. An XT, the 18-55 3.5-5.6, a tripod, and a Sigma 500 flash. That’s it no cords, no wireless transmitters, no cloning. Bonus points:
What was exposure time? I shot at f/3.5 and 400 ISO.
Yes, that is me in the white-ish shirt by the way, and no, I don’t care about my clueless expression or nappy hair (I was working all day :S).