Out of habit I still carry my old referee's whistle (very topical!) whenever I travel and also for back-up if I'm hiking in out of the way places...it's amazing how effective a few short blasts on it are if you're being hassled or accosted unvoluntarily...even the most tenacious pest is inclined to run for it if you stand your ground, take out the whistle and start blowing loudly...

#8 the scam is that the 'owner' of the money will show up, the guy you met first will say you have it and you will say no, but you will have to show him your wallet to proove it. That's the point where they grab your wallet and run away

Its a very common trick (in Asia as well) of ripping people off in the streets,usually these criminals re not alone they have partners behind the seen.
Luck you that you ignored him otherwise you 'd have been ripped off.

In the version of the scam that happened to me a third person came up showing me some ID and saying (in English) he was a policeman.
The fact that a Kiev policeman spoke English was for me the clue that this was a scam and I just walked on ignoring them
I've walked away from a police officer that didn't look right. He followed me telling I have to stop but he never raised his voice or threatened me. He eventually stopped following me and went away.
Hope more travellers aware this kind of scam. I was first time happen to me and it did not thought it was scam until after few days.
I had a Japanese guy tell me about a weird thing that happened to him where a policeman eventually asked to see his credit card.
He didn't tell me how it all started but I told him he should call his bank.
By the time he did, they had got $600 out of it.
#10 Thats a good idea!!
Raki, I suppose like all good ideas I stumbled on this one by accident...always carry the whistle when I'm out hiking in case I fall or get injured or am stranded in the mountains after dark etc...so it just happened to be in my pocket one day years ago when I was been hassled by an unsavoury character in Amsterdam...and when I turned around and started whistling loudly he bolted very quickly indeed...so now it's part of my travelling artillery...