I may well be one of the last people on earth to have heard of the conveyor belt sushi restaurants (maybe because I don't really eat sushi?), but it's an intriguing concept. Japan is where this trend originated (from all accounts) and here's a video that gives viewers a good idea of how it works.
Apparently the trend has spread. I found video on conveyor belt restaurants in Virginia in the U.S., Korea, Toronto and even a Kosher one in New York. Here's the video from the Kosher sushi bar.