I have often thought about these very same things (strangely enough)
For me it all started during my college years when a professor informed us that time was suspected to be 'quantized'
If this is true then it does bring up some incredibly strange ideas when you get right down to what happens between one quanta of time and the next.
To me this would mean that the universe would be like a cartoon or a giant 3D computer screen in which motion is actually just a series of still shots, each one remaining in place for one quanta of time before instantly jumping to a new still shot with all the 'pixels' (for want of a better word) moved a little.
Things moving at different speeds would move a different number of pixels from one quanta to the next.
Would the pixels be in fixed positions? just turned on or off as chunks of matter move through them? or would they be more fluid?
How many pixels would an electron take up?
1?
1000?
Taken to it's extreme, this concept could mean that the entire universe is actually a gigantic (insert really cool science fictiony name here) computer system running a really complex Life Simulation program.
Maybe God is a little kid playing with his dad's computer.
I even wrote a story about this a few years ago when I was holed up in an Italian hotel with nothing much to do.
You can find it
HERE if you are even remotely interested.