This isn't really Sushi, but it does come under the heading of raw seafood.
I made my second batch last night using fresh Gulf of Maine shrimp - small
yet the sweetest shrimp I've ever eaten. Check out
http://www.rickbayless.com/recipe/view?recipeID=212

I had about a cup of shelled, raw shrimp cut lengthwise leaving about 1/2"
attached at the tail end to keep the halves together. Then I de-seeded 2
Serrano chilies cut up and added to a small food processor to chop a bit.
Then about a cup of loose packed Cilantro was added to that for another
spin. Then a scant 1/2 teaspoon sea salt was added with the juice of 1 large
fresh lime. Process until fairly smooth, but don't worry too much about how
fine it is.

Plate the shrimp meats on a tray that will allow them to be 1/2 summered in
the Aguachile (stuff in the processor,) grind some sea salt over the meats
and then spoon on the Aguachile mixture. Eat right away. They didn't use
Gulf of Maine shrimp on the show, but like I said, these are very sweet.

Unlike ceviche, you don't really give these too much time to marinate which
is great, 'cause I hate to wait
--
Wilson 44.69, -67.3