It appears that there are several for sale in California at any given time. Other than that, it's rare to see them over here. I didn't even know about them until just a few months ago and I am a certified Honda fanatic.
Other than mine and a friend who lives 50 miles away, I know of no others around me. Also, it's very tempting to keep them in pristine, almost unridden condition due to their rarity so when you do discover one of them here they are probably never on the road.
Craig