What a lot of people are overlooking is the electoral college. The truth is, there are only a handful of states that decide who becomes president; the rest pretty much always go to the Republicans or Democrats.
I have no doubt in my mind that my state will go to the Democrat in the next presidential election, and the one after that, and the one after that, etc.
How I (and most people) vote has absolutely nothing to do with who wins the general election (which shouldn't even be the topic of this tread btw). All my vote did in '04 was help Bush declare a "mandate" because it helped to give him the majority of the popular vote. Maybe if more of us had voted 3rd party last time, Bush wouldn't have made such an ignorant claim and would have showed enough restraint to keep from pissing off enough people to lose both houses of Congress.
For the record, a lot of people have attributed the result of our Gubernatorial election to an anti-Bush backlash (which makes sense, considering the former gov. had a 60% approval rating going into the election).
In '08, I WILL NOT contribute to someone I do not support, only to have them tout my vote as giving them a mandate. If the Republican candidate is one of the three in my sig, I will vote Libertarian with a perfectly clear conscience.
ETA: I'm still waiting for one of the people who says it'll be my fault if an AWB is passed under the next president to take the same responsibility if it's a Republican that signs the bill.