On the train back from Leeds last night I witnessed the seats and they had some intresting patterns which one even looked like a Scorpion being forced to do front crawl. Alas I didn't take a picture of the actual seats, but i really like the idea of finding patterns amass blocks of colour and other patterns.
Other shapes i witnessed:-
Several Bats (winged animal with sonar)
Image from:- http://www.busseats.co.uk/t20small.jpg