Backgrounds can be used for menus, banners, background web
pages and also for 3D's projects as Brick texture if you
are into the 3D's
Masterdiz.com has tons of web graphics related to different
themes: Backgrounds, Texture, Wallpaper, Archeological
monuments, Pre Columbian Artifacts Mystic Cosmic Philosophy,
Transcendentalism, Fractals Space and more.