This reminds me of something interesting I once read in a book. The author claimed it was exceedingly likely that we are in fact part of a virtual reality. His reasoning was this: with superadvanced technology (nothing like what we have now, but which some alien race might have), one computer can run billions of simulations of billions of beings. In effect, the simulated entities would vastly outnumber the real beings. Therefor, it's much more likely that we are simulated than that we are real. I don't remember the details but that was the gist of it. Pretty funky if you ask me.