One of my favorite exhibitors at mail/art/book was Niko Courtelis. He commits "scandalous acts of butchery against postage stamps" and then reassembles the pieces into new works of art. They've been called Frankenstiens, but I think they're more like chimeras. You can see more of his work on his site, but in exciting news, Kat Ran Press is publishing a lookbook of the works as part of their series The Kat Ran Essays in Philatelics. You can pre-order the book here and explore their collection of stamps by typography designers here.