I started out illustrating my own non-fiction books. When I "went digital," I realized that I could be doing much more creative things and soon started doing illustrations that stood alone.
Since then I've created fantasy and science fiction book illustrations for Byron Preiss/ibooks, Delirium Books, Seattle Books, and many magazines and small book publishers. One highpoint of my work was having an illustration selected for the cover of Renderosity's first Digital Art for the 21st Century (with my work also appearing inside, too).
In addition to the artwork I have here at Renderosity, I have more pictures "for your viewing pleasure" at DuncanLong.com