I frequently vote third-party. I'm not under the illusion that they have any hope of winning.
Maybe enough of us will someday make a difference.
The US first-past-the-post system is the maker of the two-party cage.
There were some options during the primaries (like Dennis Kucinich), and this is why the primary elections are so important. None of the No-to-USA-PATRIOT options made it past the primaries, so we were left without much real choice.