Long gone. I used to read the newsgroup back when they were making them.
As I recall, they closed up shop after too many problems with quality control and apparent lack of significant research into the design. The idea was neat, but the manufacturer refused the suggestions from some very intelligent people that were trying to help mature they design to make it safer. I think there as a major pitching problem with an engine failure, blades were bending like bananas after a couple of hours and major assemblies like the main rotor shaft were being shipped out even though they were proved to be out of round and lacking consistent milling thicknesses. All in all, many think that no matter how perfectly you built a Mini500, you were risking your life to do more than a hover.
Then, one of the key builders, Gil, was killed in a Mini500.
They closed up shot shortly thereafter.