A literal belief? hehe...that's a loaded question. The story is told in every denomination, as far as I know. As far as literal belief goes, I'm not sure I can answer that for all of Christianity.
What I will say is that, once again, who and when is far less important than the concept of original sin itself. It lies at the core of our faith - without it, there would be no Christianity. It necessitates the Savior, it puts an infinite value on grace (by which faith alone can save us), it gives cause for humility in every single human being, irrespective of their place in history. Every single human sins - sin is what connects every single individual that has ever lived or ever will live. Compared to that, who and when doesn't get a lot of play, beyond Sunday school and discussions with atheists.
Did it really happen that way? Is it symbolism to explain the human condition early in our history? I have faith in God, so this is unimportant to me. It says so in the Bible, so therefore it's good enough for me - not so much to prove that it happened exactly that way, but that what is important to be learned is being conveyed the best way possible, in a book designed to speak to whoever is reading it, over the thousands of years to follow.