MandelbrotSet/Julia

That curvy one that looks sort of like an octopus tentacle with little suckers (but of course, when you zoom in, those suckers turn out to be full tentacles themselves)

: PeterTaylor boggles. Eh? There isn't a Julia set - there's an uncountably infinite family of them. The Mandlebrot set functions as an "index" to the Julia sets.

Ok, fair enough. Being an infinite family, bits of it look like all sorts of things. But the bit that ends up on PostCards looks like... --Vitenka