There is just something about the balance between black and white and the characteristics of the scratched lines that gives well-done scratchboard drawings a particular appeal. Summers is one of the best modern practitioners of the art.
He has done illustrations for major publications like Time and The Atlantic Monthly and has received three gold medals from the Society of Illustrators and was the recipient of the Hamilton King Award in 2000.
Summers is also the artist for the Barnes and Noble bookstores’ literary figures portraits. You can see them in the Prints and Posters section of the online bookstore. [2010 Update: Link is no longer valid]
Though he doesn’t seem to have his own dedicated site, you can see his work on the Richard Solomon Artists Rep site.
Addendum: 2010 update: Mark Summer’s illustrations are featured in the new book, Vanity Fair’s Presidential Profiles: Defining Portraits, Deeds, and Misdeeds of 43 Notable Americans–And What Each One Really Thought About His Predecessor.