One of the most popular pastimes among Olympic spectators is trading pins.
Groups of pin collectors gather daily at the entrance to the International Broadcast Centre, laying out their collections and swapping them with fellow enthusiasts.
I can think of better things to do than spend hours in the baking Greek sun but it seems like a harmless enough hobby.
The downside is that you're likely to get asked at least half a dozen times a day whether you've got any pins.
NBC and Greek TV have had special ones made -- the rest of us have to apologise and say no.
The number of requests has got so out of control that many of the broadcasters have put up signs outside their offices to deter fanatical pin collectors.
The Dutch, the French and the Swiss are among those who've had to spell things out.
It's the Olympic equivalent of the sign on your front door that reads "No Junk Mail. No Free Newspapers."