For my portfolio check out the special links below. I use this blog as a general hub for all my art activity : Diary, Catalog, Doodles, Musings, Reactions, Announcements, Scrap-book, video, Special Features: All art created & owned by Nate Marcel unless otherwise specified by annotation or label.
http://hellasrpg.com/
I've noticed that the Khepera Publishing Hellas RPG that I've done some illustration work for has some sweet deals on the Drive-Thru RPG site right now.