Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
A seamlessly tileable pink background texture.
Source V. Hartikainen
A background pattern with green vertical stripes. A new striped background pattern. This time a green one.
Source V. Hartikainen
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Inspired by the B&O Play, I had to make this pattern.
Source Atle Mo
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Prismatic Groovy Concentric Background 5
Source GDJ
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
Utilising a bird from s-light and some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
Abstract Tiled Background Extended 6
Source GDJ
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
This metal background pattern resembles a metal plate with rivets. Solid rivets on a metal plate.
Source V. Hartikainen