Copyright in derivative works vs. collective works

About a week ago the Ninth Circuit issued this ruling that analyzes the difference between a collective work and a derivative work in a copyright infringement case involving K2's use of a photographer's copyrighted images. This topic is not often litigated - the most famous cases I recall that deals with these definitional questions are the Nagel tile case (Mirage Editions, Inc. v. Albuquerque A.R.T. Co., 856 F.2d 1341 (9th Cir. 1988)) and the National Geographic cover case (Greenberg v. Nat’l Geographic Soc’y, 244 F.3d 1267 (11th Cir. 2001)), both of which the court relies upon in coming to its opinion that a collage of photos is a derivative work and not a collective work.