Most of the better sushi restaurants I have eaten at offer California rolls with a choice of either sesame seeds or tobiko (flying fish roe) coating the outside. The rice is almost invariably on the outside of the nori (seaweed). Bad sushi places will serve you California rolls with crab with a k.

Frater 219: You raise a good point. I have often seen such variations on the crab and avocado base theme. My favorite sushi restaurant serves cucumber in their California rolls, and I'm rather fond of them.