Forgot to mention but if you are thinking of doing one of those programs where you actually teach english abroad for a few months say, or as a gap year. They almost always include a TEFL course as part of their fee.
Do you already have teaching experience and/or qualifications?
Do you already have a planned employer, and if so, what level of qualification are they expecting you to get?
I'm off to indonesia and need some work out there.
They are screaming for native english speakers to teach English so it seems like the right move.
Looks like I'm sorted now.