Single 600EX - Bare flash off camera
I've got myself some competition here!
This has two speedlites in it... but the key light was very much like yours mchong (seriously, our names are so alike...)
The second one was just to add flare. :P
6K4A5473 by mchen397, on Flickr
IMAGE LINK: http://www.flickr.com/photos/mchen397/9403989501/
6K4A5472 by mchen397, on Flickr