Wow. Some people didn't pay attention in chemistry class.

I run a scientific instruments company, and always carry our products as cabin baggage without incident, as well as various hard-to-replace demo supplies, etc. Neon is very, very, very safe, the glass tubing is fragile-but-not-all-that-delicate, and this shouldn't be a problem. Neon can't burn (at least under conditions you'd experience in an aircraft, or on the planet, for that matter), it's non-toxic (in fact, similar gases are a major part of keeping food and wine fresh for transport), and the amount of phosphor in the tubing is far less than that in the TV screens throughout most cabins.

My biggest concern is with TSA at the checkpoints. I was recently travelling with something fraglie that only fits in it's flyaway case *one way* and one way only, and the agent *insisted* on repacking the box himself. He very nearly destroyed 5K worth of apparatus. Be insistent that when they open something, it's with you explaining how the protective layers come off, what it weighs, how it needs to be handled, etc. Do not let them rummage willy-nilly, as they don't have much regard for irreplaceable items. They figure everything is like a laptop.

Eric