TextureWorks v1.0 is an awesome collection of natural textures. Hundreds of commercial-quality brick, water, sky, stone, cloth, wood and marble textures and surfaces are included in the package. There are many different categories and whether your working on the next killer game or simply adding a background to your webpage, Texture Works is certain to have what you need.
More info:
hxxp://www.spriteworks.com/texworks.html