Stuart,
POSC is the only small PET manufacturer I have seen. But they sold their software to GE Medical Systems last year and that was the one thing that gave them an advantage over the big players.
I'm not sure what a good short-term entry point will be. I would probably buy if it dipped back bellow $0.07; but I'm not sure if it will get back down there again?
"Our houses are such unwieldy property that we are often imprisoned rather than housed in them." - Henry David Thoreau, Walden: Economy, 1854