I expelled this in about eight hours, from start to finish. It's sloppy as hell, but it's good enough for the purposes of the project. Started out with a pencil sketch (which I usually don't do) and finished in Photoshop. My model was Ben, one of my classmates for whom I recently did a bookbinding job.
The assignment was to do a portrait of a protagonist/antagonist pair (antagonist to follow soon). I chose Holmes and Moriarty, to the tune of William Gibson's "The Difference Engine." Consider: given the opportunity, wouldn't Holmes have been a hacker?