These are some interesting links that I have found on the subject of NIXIE tubes
Mikes electric stuff. Really good site not only for NIXIE tubes and projects but also strange display stuff.
http://en.wikipedia.org/wiki/Nixie_tube. A short explanation on NIXIES.
http://www.decodesystems.com/nixie.html. Another page that explains NIXIES and shows how they were used.
More coming soon.