From my understanding, all the other people are you. "You" however can only perceive the PART of you that is called LifeIsNotADressRehearsal. I am you as well, but for the purposes of the hologram, you can only see the world through the eyes of your current avatar, even though in reality, there is no difference between you or me, "we" just see the illusion of being separate.
If someone here thinks I'm off track, let me know.
Don't know if that makes much sense. It's a difficult concept, I'm still coming to terms with it. In the book he talks about your dreams and how everything in the dream is YOU. If that part of the book makes sense, then I'd apply that to the "non-dream" world (which is just as illusory as the dream world anyway).
He also says that we can't possibly really understand the problem of "other people" at our current level of consciousness. That's not the most satisfying answer.
I think according to him, everything is a part of the hologram, including "you".
If you haven't heard it yet, here's a free audio he has on this very topic on his site: Audio Discussion Of The Role "Others" Play In Your Hologram