I have to say, though, the "story teller" term really irks me. Not so much the term, but the mindset that the GM has some story that he's supposed to be telling. In my mind that attitude is synonymous with rail-roading. When the GM has a plot, then the he tries to protect it. He gets upset if the players do something to "ruin the plot". In the end, he takes choice away from the players to further the ending that he has envisioned.
It is not the GM's job to tell a story. It is the GM's job to set the stage that allows the characters to tell their own stories.
What brings this to mind is that I'll be running a game set in the Star Trek universe on Wednesday, and I've been struggling all week to come up with plots. It sounds hypocritical, to say on one hand that the GM shouldn't be telling a story, but then to say that I'm trying to come up with one. The difference is that I'm coming up with the story that is happening around the players--I fully expect them to ruin it. Maybe they'll ruin it by defeating the "bad guys" before I expect. Maybe they'll ruin it by joining forces with the bad guys and viewing the "good guys" as the villains. I don't know--the choice belongs to them.
But I need to set the stage, and I only have until Wednesday night to do it.