Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Sometimes you just need the simplest thing.
Source Fabricio
Black brick wall pattern. Brick your site up!
Source Alex Parker
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
Derived from a drawing in 'Elfrica. An historical romance of the twelfth century', Charlotte Boger, 1885
Source Firkin
A bit of scratched up grayness. Always good.
Source Dmitry
A seamless background pattern of dark brown wood planks.
Source V. Hartikainen
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
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
A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.
Source Josh Green
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
This ladies and gentlemen, is texturetastic! Love it.
Source Adam Pickering