That is an impossible thing to do for someone who is principled. Most people sit around and strategize and will find compromise even to the point of weakening. Such as voting for the lesser of 2 evils.
Well, JD, whereas I think you have a point in the general thesis of your post, I believe that your chosen course of action is somewhat misguided. I would posit that the best course of action would be to fight very hard during the preliminary part of the electoral process to either make a third party viable, or to attempt to get a more suitable candidate nominated in one of the major parties. Donate time and money to the cause, etc. If you can't get them on the presidential ticket, work hard to get candidates from that 3rd party elected to the congress or senate. However, if you live in a state that is in play, and you feel that one of the major candidates is better (or for that matter worse) for the country (not the absolute best candidate possible, just better) you should vote for one of the candidates that could actually win (unless of course it is Obama ;-0) ) Sorry, this position may not be worded as elegantly I would have liked. May try to flesh it out a bit later.