Soft Wallpaper@2X #96
 Wall  CC BY-SA 3.0

Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.

Source Atle Mo

 More Textures
Spotted Light Yellow BG Pattern #1216
 Yellow  CC BY-SA 3.0

This light yellow background pattern consists of an irregular pattern of spots. Here's a light background pattern with yellowish tint.

Source V. Hartikainen

Background pattern 306 (colour 2) #1881
 Colorful  CC 0

Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.

Source Firkin

Triangular Psychosis 4 #236
 Noise  CC 0

A colorful triangular background, variation 4.

Source GDJ

Black Linen@2X #64
 Dark  CC BY-SA 3.0

In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.

Source Atle Mo

Colorful Paw Prints Pattern Background #260
 Noise  CC 0

pixabay.

Source GDJ

Prismatic Chevrons Pattern 5 With Background@2X #470
 Dark  CC 0

Prismatic Chevrons Pattern 5 With Background

Source GDJ

Black Mamba #57
 Dark  CC BY-SA 3.0

The name alone is awesome, but so is this sweet dark pattern.

Source Federica Pelzel

Paper 2@2X #22
 Paper  CC BY-SA 3.0

New paper pattern with a slightly organic feel to it, using some thin threads.

Source Atle Mo

Inflicted@2X #118
 Grid  CC BY-SA 3.0

Dark squares with some virus-looking dots in the grid.

Source Hugo Loning

Prismatic Chevrons Pattern 5 With Background #469
 Dark  CC 0

Prismatic Chevrons Pattern 5 With Background

Source GDJ

Prismatic Snowflakes Pattern No Background #411
 Light  CC 0

Prismatic Snowflakes Pattern No Background

Source GDJ