Don't make eye contact. Ever

This basic rule has served me well for many years. Tired of random strangers oversharing? Don't make eye contact, let them pick on some other person.
And so I found myself in a great little cafe in London (she said, pretentiously) where they sell cameras and coffee and you can get free wireless if you eat or drink. Or buy a camera, I guess, but that wasn't why I was there.My intention was to pick up my email on my netbook, download any updates I needed and generally have some quiet time.

I made it obvious. Earphones in the iPhone, eyes glued to the screen. I ordered the iced coffee (really, it was hot and humid) when the chap at the table next to me said "South African accent if I'm not mistaken" I ignored him, pretending to type something deep and meaningful. He persisted, raising his voice slightly "I say, are you from South Africa?" Feeling a little like a deer in the headlights I made the mistake of making eye contact.
It took me 2 hours to get away, I didn't get to read any emails and I can now tell you that the source of any crime in the UK (apart from the government) is the (insert foreign nationals) who apparently have 10 children each with the sole intention of teaching them to pickpocket to support their families. And the vuvuzela is a dreadful instrument, which will ultimately lead to the downfall of all civilised society.