I posted this on Twitter a couple of days ago, but in case you haven't seen it...
It took me the length of a whole train journey to work out that there were a couple of unopened condoms lightly wedged into the chairs opposite me. I thought there was something unusual going on, but to be honest, I couldn't really see them behind the lady reading Fifty Shades of Grey opposite me (whose shoulder you can see in this picture, OMGZ SCANDAL), but once I'd realised they were there, I took a cheeky snap.
I wonder why they were left there? A quick surreptitious look (although I didn't take one; I've got boxes of the things at home) confirmed that they were indeed unopened, unflavoured, and within date. Was this cunning advertising? No, surely not. Durex don't need to advertise - everyone knows who they are, right? So what else would it be? @BurlesqueBun came up with an alternative explanation - that somebody had been expecting to get lucky on the train and their prospective partner had left without them - but I don't think that's very likely (in the middle of the day; I mean, maybe late at night on the Tube, but having said that, I saw someone pissing in a can at 12:30 on the train today, so anything's possible).
My theory is that someone left them there as a gift - maybe to promote sexual health, maybe to donate them to the local community, maybe just because they had some spare condoms. But maybe they were for shock value. Insofar as I'm in no way shocked by the existence of condoms, it was probably not the best place to put 'em.
But it's more interesting than having one thrown at me, I suppose.