Some typical signs of a scammer:
They immediately ask you for your Yahoo screen name or personal e-mail address, and insist that it's easier for them to talk to you on their personal e-mail address or through instant messaging.
They tell you their e-mail address in a format such as myname(AT)Yahoo instead of just typing their address.
Their photos are modeling shots (They usually steal them from other web sites)
They have very poor English, yet they claim to be from the US or UK. Not a sure sign of course, but if you are talking to a blonde caucasian from Alabama and she talks like English is a second language, it's a clue.
They tell you that they are a model, working as an IT specialist or a businessman traveling.

SCAMMERS...My personal take on this issue..It is unfair and discriminating if people will accuse a person of being a scammer just because he/she came from a third world country.If there is something wrong with his/her grammar.In my own words,,WAG KAYONG TAMANG HINALA NO.