Add Akshay Rustagi (posted from Craiglist) to the list of scammers. Their usual trick is skype chat or talk. The best way to identify scammers is to talk face to face.
More people have been scammed face-to-face than over the internet. I am currently reading Robert Greene's The 48 Laws of Power, and he discusses many actual cons that have taken place over the years. My favorite is where a guy got $5000 out of Al Capone.