Just curious, I believe it's possible no doubt about it. But can you do things like, meet up with other people and talk about it the next day? ask a friend to write a piece of paper at random, leave it in their room, and tell it to them the next day, etc?
it is both, and neither
Its called lucid dreaming, you can't separate your soul from your body as you don't have a soul. If astral projection was "real" then the government would be spending millions of $$ to secure the services of a bunch of stoners.
If you honestly believe that you have a soul can i have your brains?
It is pretend.
As far as I can tell it would be very simple to test under scientific conditions. In my opinion there would be a lot of scientists who would love to be the ones at the helm of this revolutionary discovery, as long as the results were conclusive. If it worked, I think we would know about it. If it can't be proven we should really not worry about it, it's just an halucination.
Charles Tart's experimentation with "Miss Z" is an example of this:
http://www.psychwww.com/asc/obe/missz.html
A big logistical problem with meeting up with others is finding sufficiently talented partners to ensure both are 'out' simultaneously. At the Monroe Institute (where they train a dozen people simultaneously) such verification is apparently commonplace - lots of personal accounts are out there if you look. Googling "partnered exploration" will also give you a few Bruce Moen hits of possible interest.
It personally took me about 22 years to achieve this sort of validation. Though it sounds like a piece of cake, in practice it's a bit like solving equations while you're drowning, there's an awful lot going on to distract you...
It is actually more real than the physical reality.
Yes you can meet up people and talk about it the next day. It is hard to read something written on a piece of paper.
It's more that real people can see things behind walls or talk to other people.it's like leaving your physical body and flying.
I don't think it's a hallucination.
A hallucination is if you see a lepracon in stead of a tree but if you see places that exist or see things in a different way without changing them it's not a hallucination.