Although most places use imitation crab, I'm sure that you'd be able to find places that will also offer the california roll with real crab. It's typically a buck or two more per roll. I've made them with crab meat from a can and I think it's pretty good.

I was in Hong Kong and Tokyo five years back and the california rolls in Hong Kong were pretty crappy. However, I'm kind of drawing a blank as to why (I just remember emailing my gf that the sushi in HK wasn't as good as in Vancouver). For some reason I think they were made without the avacado (I don't know how you can call it a california roll without avacado). I was in HK for 6 months and we went to a number of sushi places.

I don't recall seeing califorinia rolls in Tokyo. But that said, I was only there for about 5 days and didn't have a chance to go to a lot of sushi places.