Texture Analysis and Synthesis Links
List of links to other 3d/texture sites, but most of them are dead links.
Bad link.

Texture Library - forrest.cz
Big library of textures choose on the Internet for free - Photos in jpg format.
Read the info section about limitations for commertial use.

Textures - astronomy.edu
Paul Bourke Textures Free to download - Big and good collection in jpg format.

TEXTURES AND BACKGROUNDS
Photos by several authors in jpg format - Different resolutions and quality.