We experienced a variation to this scheme (or scam!) last weekend in Paris. Someone close by bends down and picks up a "gold" ring and asks it if it yours. When you say no they say you are a nice couple please keep it, but can you give me some Euros to buy something to eat. Needless to say we declined their kind offer!
I've not experienced that one before, but we saw two other people trying to do exactly the same thing later in the day.
In the cold light of day you always feel "how could anyone fall for it" - however their method is always to take you by surprise and off guard and it must work often enough to be worth their while.
