English: "real" as adverb?

I've come across "real" used as an adverb quite often lately, in expressions like "that would be real nice" or (just now in Joshua Kadison's Jessie) "drive real fast". At first I thought it was a mistake because it was one particular non-native speaker who kept using it but now I'm a bit confused.

Is this use correct?
Is it equivalent to "really" or used in different contexts, by different people, in different regions?