Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
This background image has seamless texture that resembles a surface of gray stone.
Source V. Hartikainen
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight