Best graffiti ever!
I very rarely bother to use the camera on my mobile, for two reasons: firstly, the camera is crap; secondly, people taking photos on their phone kind of annoys me. It’s irrational, but it does.
Anyway, a couple of weeks ago I was visiting a friend who lives not too far from East Finchley tube station, and as I was walking along the road towards my destination I noticed one of those funny big metal boxes that you get on pavements, which presumably have some electrical stuff in, or something to do with the phone lines. Anyway, the reason I noticed it was that someone had decorated it with an example of integration by parts:

How odd is that?!