I just got back from a week in Okinawa (to be more precise, on the islands of Ishigaki, Taketomi, and Iriomote, which are way down at the end of the Okinawa chain, near Taiwan). Perfect weather, white beaches, blue ocean...ahh...
I stayed mostly in minshuku, the Japanese equivalent of bed & breakfasts, although they usually include dinner as well, so I got to have a lot of home cooking. Okinawan food is quite different from that of mainland Japan. There's the use of different fruits and vegetables, like goya (a bitter gourd that is referred to in mainland Japanese as nigauri) and green papayas. There are a lot of stir-fried dishes, collectively referred to as champuru. The local tofu is extremely dense (in the supermarket, it's generally sold in plastic bags, still warm). There's also jimami tofu, made with peanuts. And then there's the use of... SPAM. Boy, did I eat a lot of Spam--it pops up in scrambled eggs, stir-fries, you name it. The supermarkets even had several different brands of "luncheon meat". It's the American military influence, combined with the island thing, I guess.
I also ate a lot of soba, which despite the name, is what's called ramen up here. In general, the local version seems to either come topped with pork ribs or with slices of pork, but has a very light soup, which is nicely accented by hot pepper sauce. (Apparently there's also a pig's feet version, which I chose not to go for! Okinawans seem to be very efficient pig users--pig's ear also shows up on the table in some places.)
And then there's the local ice cream...all sorts of funky flavors like mango, purple sweet potato...yum.
There are quite a few Okinawan places in Tokyo, which I'll have to go exploring. Don't know about any outside of Japan, but if you come across any, I'd recommend giving it a try.