It's not like you can build a material library out of such things; each and every time you use it (much less anyone else), you have to properly unwrap your object. And the bump map height will always be just as tied to the mesh as the texture. Making libraries of materials out of UV textures? No. The only step it would save you is caching the path to the texture and bump images. And that's only assuming you don't move anything.
Perhaps a "challenge" to see who can post a link to the highest quality, highest resolution, most usable, most royalty-free, etc. online texture image repositories is a better idea.
