I found this essay regarding the origin of the California roll - interesting!
http://www.thesushibar.com/sushi_chi...CaliforniaRoll
Quote:
The California Roll (Kashumaki or Karifoniamaki)
Though maligned by a few sushi purists who don't even recognize it as legitimate sushi, the ubiquitous California roll is the most popular roll served in American sushi bars from coast-to-coast. It is most Americans first introduction to the world of sushi. Indeed, many novices incorrectly call any makizushi a California roll. I routinely get asked, "Do you have any of those California rolls without the seafood?" and "Do you have one of those California rolls with the grilled eel?" Though the California roll has become popular around the world, it bears only a slight resemblance to authentic, Japanese fare; being as the name implies, a California creation. It has even been exported to Tokyo, Japan, where it has been well received. The Japanese deem our lowly California roll as foreign and exotic as western movies and Hollywood.
Its genesis was at the now defunct Tokyo Kaikan restaurant in the Little Tokyo area of downtown Los Angeles. When Mr. Mashita created this roll in the early 70's, I'm sure he had no idea of how enormously popular it would become. His inspiration rapidly altered the course of "America sushi" forever, and has led to a plethora of inventive creations. Now, almost every sushi bar has their own unique variation.
I was fortunate enough to interview Ms. Kimie Kawasaki, who worked with Mr. Mashita when Tokyo Kaikan was in its heyday. It was originally made with imitation crab (kani kama), flying fish eggs (tobiko), wedges of avocado and wisps of shredded cucumbers. Mr. Mashita rolled these ingredients, inside a crispy sheet of rice lined toasted seaweed (nori) and cut it into six pieces, with the dark green seaweed on the outside, nakamaki style. Today, there is no single style of California roll. In the intervening quarter century since its humble birth, the California roll has evolved into as many variations as there are sushi chefs. Some of the more popular styles follow.
Mr. Mashita's prototype notwithstanding, today's California rolls are usually served inside-out (uramaki) with rice on the outside. They are almost always composed of three basic ingredients: crab (kani) or imitation crab (kani kama), though sometimes shrimp is used; avocado; and cucumber. Three other fillings are also commonly used: smelt roe (masago), mayonnaise and toasted sesame seeds (iri goma). The kani or kani kama is typically mixed with mayonnaise and masago, and placed in the center of the roll along with cucumber and avocado. Sesame seed dotted rice often graces the outside of the roll. In another popular variation, the kani is broken apart and mixed with mayonnaise, while masago adorns the outer rice. Sprinkle toasted sesame seeds on top of this attractive version as a tasty garnish.
We make several kinds of California rolls where I am currently employed. Our most popular variation uses tiny tender, parboiled bay shrimp, which are marinated in the juice from sweet pickled ginger (gari). The ginger adds a delicate, spicy-sweet flavor to these tasty morsels. When combined with rich, creamy avocado they make an interesting juxtaposition of flavors and textures.
Of the spicy variations, the Baja California roll is my favorite. Its mild heat and zesty flavor comes from slivered seeded jalapenos. Another spicy roll, the Kamikazi California is kicked up several notches with strips of unseeded habeneros. Warning: the Kamakazi is a real scorcher - far too intense for most. When a customer requests a spicy California roll most chefs just add their house spicy sauce to obtain the necessary Scoville. I know of one Hawaiian chef who uses emerald hued wasabi tobiko (flying fish roe) to spice up his bejeweled artistic creation.
In one of the most popular formats, the kani (invariably kani kama) is left in sticks or chunks and no mayonnaise is used. Masago is instead, placed on the inside, or spread on the outside, trading places with sesame seeds. Some chefs add yamagobo (pickled burdock) to the middle, or layer thin avocado slices on the outside of the roll, caterpillar roll style. I have also witnessed a shokunin center small mounds of masago (or a mixture of masago and mayonnaise) on top of each cut piece as a feast for the eyes and palate. Dried bonito shavings (katsuobushi flakes) and shiso leaves are also employed for a similar purpose, usually in the hand roll (temaki) versions. The number of possible variations are limited only by the imagination and virtuosity of the sushi chef.
One of my all time favorites is the Baked Scallop California roll: (B.S.C. roll). A B.S.C. is simply a California roll that is topped with scallops and baked. To prepare, spread about 1/3 cup of a mixture of chopped scallops (hotategai), smelt roe (masago) and mayonnaise on top of a finished California roll (a dash of shoyu is optional). Bake or broil for eight to ten minutes until done. While baking, the sweet, succulent juices from the bubbling scallops seep through the warm sushi, imparting an incredibly wonderful flavor to an already tasty roll. After removing it from the oven, slide it from its greased baking sheet and onto a serving tray. Sprinkle with black sesame seeds (kuro goma), and serve hot. Caution: allow to cool slightly before voraciously devouring it.
I could go on ad nauseam about the selection of avocados (I prefer the dark, bumpy surfaced Hass over the thin skinned, green Florida variety), whether it is nobler in the mind to mayo or not to mayo, or the subtle differences of using smelt roe (masago) vs. flying fish roe (tobiko); etc. But I feel part of the fun of the California roll is in the discovery of all the unique and interesting permutations that abound.
But it's really difficult to figure out how to count it! 
