Tiling Plain and Fancy
Tiling from the mathematical and historical viewpoint by Steve Edwards. Provides a number of examples of various types of tiles that tile the plane and includes periodic tiling plus Penrose's aperiodic tiles.
http://www2.spsu.edu/math/tile/

Mathforum : Minimal Domino Tiling
Tiling a square without cutting it into two.(Problem of the week 826, Spring 1997)
http://mathforum.org/wagon/spring97/p826.html

Unbalanced Anisohedral Tiling
Joseph Myers and John Berglund found a polyhex that must be placed in two different ways in a tiling of a plane, such that one placement occurs twice as often as the other.
http://www.angelfire.com/mn3/anisohedral/unbalanced.html

The Penrose Tiling at Miami University
A summary of the history behind the Penrose tiling in the math department at Miami university.
http://www.lib.muohio.edu/epub/tilings/doc.html

A Bit O Blarney
free Irish wallpaper, Celtic wallpaper, shamrocks wallpaper, ireland wallpaper, wallpaper with Irish designs
http://www.abitoblarney.com/irishwallpaper.htm

Grotesque Geometry
Andrew Crompton's tiling and tessellation images.
http://www.cromp.com/tess/home.html

Jimpix
free christmas ecards and free christmas greeting cards for people with warm winter coats on, free christmas e-cards, hi-res desktop wallpaper designs, some photography, and a load of open-source flash flas
http://www.jimpix.co.uk/

Mike Field
University of Houston. Graphics and resources in symmetry and tiling.
http://nothung.math.uh.edu/~mike/

Polyomino Tiling
Joseph Myers classifies the n-ominoes up to n=15 according to how symmetrically they can tile the plane.
http://www.srcf.ucam.org/~jsm28/tiling/

Rectifiable Polyomino
Tiling rectangles with polyominoes.
http://www.eklhad.net/polyomino/