A couple of years ago, I taught myself some rudimentary PostScript programming from Bill Casselman's brilliant Mathematical Illustrations book. PostScript is excellent fun, and I thoroughly recommend it to all weirdos with an interest in stack-based graphics programming.
Recently, while fiddling with MetaPost (another perverse but entertaining graphics language), I remembered using Python and PostScript to create a nice Bezier curve approximation to a cycloid. This was before I discovered PyX, which does that sort of thing for you, and it's a very illustrative exercise - but my not-quite-right first attempt actually produced a fascinating and very pretty result:
While the code that produced it is long gone, I'm happy to still have the result. Only mathematical illustrations can produce such satisfying errors... and just imagine what someone talented and artistic could do with the right mathematical/programming knowledge.