Richard Jones' Log: Patterns in Python
Melbournians will recognise the pattern (I hope ;) For non-locals, the pattern adorns the external walls of Federation Square here in Melbourne. I think it's pretty cool :)
Code to generate it (requires pygame).
The pattern is called "Pinwheel Aperiodic Tiling" and is named for the pinwheel shape I've highlighted. Click the thumb for a full-size (well, 640x480 anyway) pattern.