You can find information & resources of science, biotechnology, chemistry, ecology, technology, science resources, mechanical engineering, earth sciences, astrophysics, nuclear & molecular at PortalScience.com
Tessellations
A company selling foam puzzles, many based on planar tessellations (tilings) and fractals.
http://www.tessellations.com/
William's Geometric Construction Page
Activities to create patterns using simple resources, such as making equilateral triangle from a circle. Suitable for upper primary and lower secondary ages.
http://www.cyffredin.co.uk/