Not voting is a statement on our political system. Look at that, we're equal again.
I don't think straight-up not voting works that way, because you'll just be seen as part of the apathetic group rather than not voting for a reason.
To make your not-vote actually mean something you'd have to do what the hippies and the like did with their draft summons by organizing, going somewhere public, and burning your ballot sheet or something. Then it's a political statement.
(Note: I'm not saying I agree with that action, but just pointing out that not voting in and of itself isn't a political statement until you make it known in a highly visible manner)