Light Aluminum #304
 Wall  CC BY-SA 3.0

Used correctly, this could be nice. Used in a bad way, all hell will break loose.

Source Atle Mo

 More Textures
Silver Scales@2X #190
 Light  CC BY-SA 3.0

Turn your site into a dragon with this great scale pattern.

Source Alex Parker

Dark Brown Wood Background (Tile-able) #886
 Wood  CC BY-SA 3.0

Tile-able Dark Brown Wood Background. Feel free to use it as a background image in your designs or somewhere on the web. By the way, the color seems to be close to Coffee Brown.

Source V. Hartikainen

Prismatic Groovy Concentric Background 4 No Black #463
 Noise  CC 0

Prismatic Groovy Concentric Background 4 No Black

Source GDJ

Retro Squares Background 4@2X #419
 Dark  CC 0

Retro Squares Background 4

Source GDJ

Seamless Cardboard Texture #1212
 Cardboard  CC BY-SA 3.0

A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.

Source V. Hartikainen

Prismatic Abstract Geometric Background 2 #268
 Noise  CC 0

Prismatic Abstract Geometric Background 2

Source GDJ

Background pattern green #1953
 Green  CC 0

To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Elegant Grid@2X #317
 Wall  CC BY-SA 3.0

This is a hot one. Small, sharp and unique.

Source GraphicsWall

Prismatic Curved Diamond Pattern 4 No Background@2X #542
 Diamond  CC 0

Prismatic Curved Diamond Pattern 4 No Background

Source GDJ