There's a few shots of Neo where he's doing the "Superman thing" and flies up into the atmosphere above the cloud layer. This got me to thinking: if we were to assume that the Matrix is essentially a virtual reality game, then there would logically be some kind of border or boundary surrounding the "game world" that is impassable. Is there any known boundary limit in the Matrix? Could someone (Neo, someone plugged in with a proper vehicle, whatever) decide to, say, visit the Moon? Mars? Alpha Centauri?
As a computer programmer I don't see any logical reason why the Matrix couldn't be procedurally generated. You could probably have a universe large enough that it would take many lifetimes moving at the speed of light to reach the edge. This also makes sense when you consider that the Matrix does not actually have to render the environment where no one is present, until someone actually goes there. So a large universe might not really overburden the hardware. There is also no reason why the "Architect" couldn't receive an alert when someone gets 80% of the way to the edge so that the machines can either start building additional capacity and content (or just kill the person to save themselves the trouble). I seem to recall the Architect saying something to the effect that there had been multiple versions of the Matrix. He also seemed to suggest that much of humanity had been killed off at the end of each iteration. So the capacity limits and boundaries may not be static but could depend on version number and the size of the human population.