Drawing diagrams with CSS. Yes, CSS!
Whilst searching for some enlightenment on UML state diagrams, I came across a rather clever use of CSS to draw a diagram.
I never would have thought that you could use CSS to draw a diagram, never mind a clear, professional looking one, but this guy managed it with aplomb.
The author claims that his only other option was to use MSPaint, but I think he probably had too much time on his hands really 
