A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
A seamless pattern formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Retro Circles Background 7 No Black
Source GDJ
Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Greyscale version of a pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The image is the remix of "wire-mesh fence seamless pattern" .This is a more minute version of it.Sorry for the file size.Using path>difference in Inkscape, I will cut out any silhouette from this pattern and create a "meshed silhouette".
Source Yamachem
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
Background pattern originally a PNG drawn in Paint.net
Source Firkin
Prismatic Curved Diamond Pattern No Background
Source GDJ
The image depicts an edo-era pattern called "same-komon" or "鮫小紋"which looks like a shark skin.The "same" in Japanese means shark in English.
Source Yamachem
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic Triangular Seamless Pattern III With Background
Source GDJ
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.