Having just returned from a week in Paris which was wonderful, it is worth mentioning a couple of scams which are being pulled on the streets to catch out the unwary tourist.
The first is when a person approaching you bends down and picks up a gold ring from the ground, claiming to have just found it lying there, and then tries to pass it onto the approaching tourist as "good luck" for having found it, in return for some Euros. This happened to us 3 times during the week. The 2nd and 3rd time we actually saw the "slight of hand" as the individual already had the ring in their hand as they bent down to pretend to pick it up.
The second is being approached by people (usually working in groups of 2 or more) carrying what looks like official forms and being asked "Do you speak English?". I am not sure what exactly the scam is - possibly to distract attention whilst one of the group attempts to get into your bags or pockets? But I do know that after being approached by 2 women in this way, they were swooped upon by the local Police and taken away. On other occassions we saw tour guides quite forcibly declining approaches of this nature made to members of their group. We always just said "Non" at the initial approach and moved on.
Experienced tourists may well be aware of these scams, but hopefully this post may stop someone less aware from being taken advantage of.