The way it breaks in older browsers is incredible, and far more diverse and interesting than I would have ever imagined.

Chrome 17, Firefox 3.6, Chrome 9, IE 5.1.7 Mac:

https://twitter.com/waxpancake/status/991412919656005632

Opera Mobile:

https://twitter.com/coreh/status/991395667720507393/photo/1

Opera (unspecified older version):

https://twitter.com/dz/status/991365966553591808/photo/1

IE 9 (my personal favorite):

https://twitter.com/jamieparkinson/status/991329118267609088