I made a Processing hack based on distributing the color space over the Hilbert curve.

http://www.openprocessing.org/visuals/?visualID=2178

My wife liked it so much she made a quilt based on it

http://www.flickr.com/photos/abulafia/2896382435/sizes/o/

That's awesome! I plan to have a large print of my Hilbert portrait made for my study wall. I'm a bit enamoured. ;)

I uploaded a tool I've written in SML for generating space-filling curves (Hilbert, Peano, Sierpinski) with postscript output on github: http://github.com/soeren/snippets/tree/master/spacefilling/

A long while ago (right after xkcd posted his Hilbert Curve map) I started doing whois lookups and rendered a real-life internet map based on IP block owners. I never rendered all of the data I retrieved and have subsequently lost the raw data I collected, but here's where I was about 8 hours into the weekend project (warning, 4096x4096 image): http://farm1.static.flickr.com/143/325132490_77ae2dac5f_o.pn...

You might be interested in my visualisations of an IP geolocation database on the Hilbert Curve, also inspired by xkcd:

http://corte.si/posts/code/hilbert/explorer/index.html

Yea I'm pretty sure you stole my idea :). Just kidding. It looks very cool!