Here's an yet another background for websites, with a seamless texture of wood planks this time.
Source V. Hartikainen
The name Paisley reminds me of an old British servant. That’s just me.
Source Swetha
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
Light square grid pattern, great for a “DIY projects” sort of website, maybe?
Source Rafael Almeida
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
A free background pattern with abstract green tiles.
Source V. Hartikainen
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
An alternative colour scheme to the original seamless pattern.
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
A seamless pattern formed from a tile made from ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
A version without colours blended together to give a different look.
Source Firkin
An alternative colour scheme for the original background.
Source Firkin
Redrawn based on a drawing in 'По Сѣверо-Западу Россіи' Konstantin Sluchevsky, 1897.
Source Firkin
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim