Well, from a fellow Geocacher (Yes, this is also my GC handle) I think it's cool! I can see something like this, if the actual cache was located on the grounds of an old Nike missile site. (yet another one of my many odd hobbies).. Yes, the terrorist have put a major dent in the hobby, but it still has its fun times.. How long does the whole thing run for, seeing only a 6V supply (or is that 4.8, Rechargable?) being boosted to 180V for the nixie tubes, must be brutal on batteries!