This idea came to me quite a few months before this posting, but the idea revisted me several times, and after becoming spine-tinglingly excited about the concept a few times, I had to post it.
So I've been refining my thoughts on the single particle universe theory, and figured I should post it here for comments before I forget about it, and before I read up too much on other people's theories along the same lines.
Here goes...
Man has long quested for the indivisible elementary particle, hoping to find that single type of particle that comprises all things...
Now imagine for a moment that such a particle exists -- but instead of the Universe being comprised of countless billions of trillions of these particles, there is just one.
One single solitary elementary particle... that exists outside of the regular constraints of the laws of physics. One particle that exists outside of time as we know it.
If this particle existed outside of time, it would be possible for it to be in many locations in space at once from our perspective -- after all, it would have all the time in the Universe to get there.
Not only would this particle be the fundamental primary building block of the Universe... it would also be the entire Universe at the same time.
This one particle would be all matter, all energy and all time and space all at once.
For the religious... this particle would be God.