At the end of last week I advertised a car (Alfa with engine en panne) on French ebay. I quickly got a response from a nice-sounding man who was prepared to pay full price and collect the car in a week or so. He said he'd send me money via Western Union to reserve it for him. This morning he emailed to say the money had been paid, and sent me the code number to check on W Union website -- but also a long story about needing to make a call to a "postmaster' to get instructions on how to receive the payment. However on the W Union website it was clear that you could just go to the local PO to collect the funds, which I did -- but when I got there they told me, first, that the money was coming, not from France as I'd assumed, but from Cote d'Ivoire -- and second, that the recipient's name was different from my own. As there's a note at the bottom of the form warning people not to go ahead if this happens, I realised straight away that I was being scammed. Not quite sure how this works (ie if they make you change the name on the form) but very glad I escaped in time -- though sorry not to have sold the Alfa.
So -- if this happens to you -- watch out!