Read the usage note here: http://www.thefreedictionary.com/different
Is there a difference between:
That's different from _____________.
That's different than _____________.
I am not a teacher.
Different from is my preference too.
I know that different than is correct, so please don't bother pointing that out to me, but I never use it myself and it always jars when I hear it.
This is a purely personal point of view but the than makes it feel like a comparative and I expect to hear that something is differenter than...
You can use 'different from' all the time. It will always be right, though not necessarily the best choice of preposition.
You'll also hear "different to".