Personally, I like to think of the universe as a static sort of space-time structure (I drop one spatial dimension so that I can visualise it). At one end, it tapers off to a point. The other end just keeps getting larger and larger as we move away from the tapered end, kind of like a cone.

Now, what's "before" the tip of the cone? Well, if you don't have an occilating universe model, you can say that there is no more cone-material there. But the cone-material is space and time.

Then, there is no space or time before the bang. No matter either, because matter has to be in the space. No quantum fluctiations either -- they too depend on time and space. Don't worry though, this isn't "something coming from nothing". I mean, if you were to construct your own little cone out of wood, does the fact that it has a tip mean that it was created from nothing? No, you made it out of wood, not nothing. [img]/phpBB/images/smiles/icon_smile.gif[/img]

In my opinion, the universe is either all there is, or it is made from something we cannot detect. (Definition of "universe" is subject to change [img]/phpBB/images/smiles/icon_smile.gif[/img] )