I love nixies. I have a Fluke 8100 with a nixie display; it's pretty much just my battery tester but the most beautiful (and largest) one in the world.

Also built a kit clock that wasn't much more expensive than just one of this guy's tubes (uses Russian surplus pc-mount tubes), but apparently no longer available.

I think I got it here, but the site just shows some lame SQL error now:

http://www.store.tubeclock.com/