Good stuff.

Also,

    The picture of Klein’s quartic curve was made by Greg Egan, and you should also check out his page on Klein’s quartic curve.

For anyone curious, Greg Egan writes interesting hard scifi. A particularly interesting and hardcore piece of scifi which rests on a significant pile of graph theory et al. is his novel "Schild's Ladder." [1] (one of these days, one of these days I am bound to attempt to finish it..)

[1] http://en.wikipedia.org/wiki/Schild%27s_Ladder