There are quite a few. The most recent scams ask you to pay the full price and they will ship it to you but quote the fact that you are covered through ebay if it goes wrong, even though it wouldn't actually be through ebay as it is classified and I *think* you have to use paypal.
The other main one at the moment is just harvesting contact details, you can usually tell those by the ones that ask you to email them in the listing.