I didn't get pictures at the time, but I had an RCS riding on top of a floating blue Ramshorn the other day. The Ramshorn was hovering in the middle layer of the tank and the RCS swam over and perched upon his shell.
The Ramshorn just kept floating along with the RCS on its back, it was so cute.
It'd be awesome to train them to become SSS, my ramshorns float themselves to move around the tank all the time and occasionally a shrimp will perch on top of a floating snail, I'm sure it happens more than I can catch because I've seen them riding on top of snails while they climb up glass all the time!
Would you buy a shrimp if it surfed your snails all the time?! That'd be sweet.