Anything

This is a really quality article on the topic. I've been playing around with dithering recently (c.f.) and it's very cool to learn more about the mathy aspect.

One thing I've wondered about is the potential in dithering that isn't stable over time, or, better, that is semi-stable. Animation effects could be very cool if not too visually overwhelming; I'm thinking of how some pixel art has been animated by cycling a color palette.