From John Kremer's book, "1001 Ways to Market Your Books":
"You should have business cards printed up with your name and the title of the book or books you are currently promoting. You might even want to have the cover of your main book reproduced on the back (or front) side of the card. Once you have the cards, give them to everyone you meet who might have any interest (however remote) in your book."
Do the same with book marks!