Parody / Theft / Inspiration

There is a lot of discussion right now at www.spd.org over what is parody, what is theft and what inspiration when it comes to borrowing or blatantly ripping off someone's design. Here is a fun

link to a site that showcases some very close calls. Anyone in the creative/design world has surely faced this debacle as we all look at the same stuff, same books, same magazines, etc.