[quote=Nimda]
My AP/IB/GT English teacher said that "All right" was outdated, even in formal speech, and to use "alright" instead.
[/quote]

Now that is something very untrue. No school of grammar sees all right as outdated, and all still prefer all right. One person's opinion is not that of the people who make the language. But since it's not heavily controversial, unlike the Oxford comma debate, unless one makes a big deal about it, it's each to his own. And I'm not going to make a big deal out of it (unless you say it's outdated).