Yes Ranger, they still have them, but they are falling out of favor now that LEDs are more available.
Back a few years ago, when I was putting up movie theaters, we were also using "nuclear" exit signs. The glow was actually put out by some sort of reaction - had no power source. Someone here can probably shed some more light on what the actual chemical process was for those signs. First time I saw them glowing in the back of the truck it kinda freaked me out a bit...
