Reversible Seats
I once saw reversible seats on a Hong Kong ferry, but they were dinky wooden benches with the backrest tilting one way or the other. These seats on a Sydney train looked like sturdy permanent seats until I saw someone push the yellow handle and voila! Like a magic trick it was facing the other way. A clever design with a rotating back and armrest. The two advantages to this are 1. a group of 4 people can sit facing each other anywhere in the train, and 2. everyone can sit facing forward instead of the common half forward / half backward arrangement. Very clever.