I didn't really start anything, I just saw them being offered as appetizers at restaurants, and featured in some of the food magazines, so I thought I'd try them.
There are some videos on youtube, I think. My patties are about 1/2 inch thick and about 2.5 " in diameter.
It's a refreshing departure from the hamburger arms race I see at fast food restaurants, where they offer larger and more complex burgers, mostly with cheese and bacon, and everything else you can think of.
I use a relatively hot pan to sear the meat and keep the juices in. Because they're small they cook fast, and that's one of the things that makes them good. You can get a well done burger that's still juicy.
I have seen White Castle hamburgers in the frozen food section of large supermarkets in the Minneapolis area, so you may find them near you if you're homesick for them.