I saw an interesting post on Marc Cantor's site: a picture of his daughter Mimi, next to a computer which has a picture of a computer, which has a picture of Mimi. Marc asks "Which Reality is Real?"
Of course this is a trick - the answer is "none of the above"! The outermost reality is just a web page with a photograph. In fact, as you're viewing this right now you have - a web page with a photograph of his web page with a photograph! Which reality is real, indeed?
This type of confusion of levels was the specialty of René Magritte, one of my very favorite artists. His most famous work is a simple painting of a pipe, with the caption "ceci n'est pas une pipe" which means "this is not a pipe". At one level you are tempted to say "wait a minute, that is a pipe!", but then you realize "oh, it isn't a pipe, it is a painting of a pipe!". Of course this is neither a pipe nor a painting, this is a web page with a photograph of a painting of a pipe.
This same confusion of levels is at the core of the Matrix movies - a reality which is a simulation within an outer reality. At the end of the Matrix Reloaded we understand suddenly that the outer reality is also a simulation (!) nested inside a reality another level out. I wouldn't be surprised if the conclusion in the Matrix Revolutions is that all reality is a series of nested realities, with no "outermost" level.
I urge all of you to take a screenshot of this page, and post it on your website. Then you'll have a page with a photograph of a page with a photograph of a page with a photograph... For even more fun, view it through a mirror. Which Reality is Real, indeed!