People on the underground are so funny to watch sometimes - When you are not in a hurry and they're not in your way....
I was on the way up the Jubilee line escalator at Waterloo when I noticed that the guy ahead of me was shaking his hips in a barely restrained way.
Not epilepsy, but ipod.
He was listening to music and trying not to boogie.

As I glanced over to the escalator going the other way, I found that almost all of the other cattle class commuters were doing the same thing.
An underground, silent disco, punctuated by security announcements that no one can hear because they are all plugged into their pods.
Party on..........