"This is a toy for building complex 3D polyhedral shapes from simple ones by "recipes"polyHédronisme allows you to construct various polyhedral shapes (only 3 dimensions though!) by composing rules over various bases, for example starting with a plain octahedron
The second is the every popular Element of the Week via the The Guardian newspaper. A fun introduction of the basic building blocks of chemistry and each week a new element. This week, the famous and well known element: astatine .
I recommend you check out caesium, rubidium, potassium and sodium for the sheer fun of watching those being dropped into water and reacting violently. Such experiments are now banned from schools for safety reasons, along with many other aspects of science unfortunately...
Failing that there's the Royal Society of Chemistry's Visual Elements Period Table which is great fun.
And finally, for the squeamish of you stop reading now, for the less squeamish its probably best to avoid mealtimes, but this is great:
Introducing a new beast more or less regularly (if not every day). To understand this site you can read their introduction which helpfully has no pictures to put you off your food.