On the 3 party thing, I've always considered myself an Independent voter, the left is too far left for me on some issues, and the right is equally too far right on some too. I agree with about half of each party, but cannot get 100% behind either one.
As someone mentioned earlier, the fact that these two parties could only produce these two candidates is pretty sad. Mark laid out why we have a two party system, but also if we were to have 3 parties, and say they were evenly split, 33% support of each, then no matter which party won an election, the other two parties, or a 66% majority of the population, would then be governed by a clear 33% minority, and nobody wants that.
I think both R+D are willing to submit to being governed by the other, as long as it's about a 50-50 split, they know the pendulum will swing back to their side eventually, just like it's been doing for years. 8 years of Clinton, followed by 8 years of W followed by 8 years of Obama.
But nobody wants a 3rd party to contend with, because the devil you know is better than the devil you don't know.