Nice reference Tilt. I was going to say that collage is comparable to making maps from others' symbols/shapes or bits - you beat me to it.
Let me quote from that article:
(Quote from http://www.funnystrange.com/copyright/derivative.htm copyright © 2000, 2001 by Sarah Ovenall)Most important to the collage artist is that a derivative work can only include copyrighted material if it is created by the owner of the copyright on the original material, or with that person's permission. This means that making a collage that includes photos from National Geographic, Rand McNally maps, or pictures of Andy Warhol paintings, is illegal unless you have obtained permission from whoever owns the copyright on those works.
I have been told that copyright law does not apply to collage as it does to other derivative works, because collage is recognized as a special art form worthy of special protection. Nothing in my research confirms this or anything like it. So I am sadly forced to classify this as a myth. (Would that it were true!)
Please note that the law is unequivocal: "Only the owner of copyright in a work has the right to prepare, or to authorize someone else to create, a new version of that work." This means that, if you want to get technical about it (and I assume you do, or you wouldn't be reading this) an unauthorized derivative work is illegal from the moment you create it. It doesn't matter whether you publish 5 copies or 5,000. It doesn't matter whether you sell the collage for profit or give it away. The act of creation is the infringement.
-Rob A>