Rather than just "a third party", I'd rather a number of "third parties" would prosper and grow, the Greens and the Constitution parties among them. (A friend of mine's father - Howard Phillips - helped found the Constitution party and ran as it's presidential candidate three times.)
I think if the American people were to start seriously considering parties other than the two majors and if the two party system were to break down a little further than it already has (and it is breaking down) the people of the United States would be far better off. Not because there would be further splintering and divisiveness - but because it would eliminate the flip-flopping back and forth between each of the two parties being the dominant one. It would require true cooperation between multiple parties to get anything done.
The two major parties are too strong - and have grown too arrogant as a result. They are two focused on trying to retain their power - instead of working to solve the problems that need solving.
Having a number of potentially viable parties would require more cooperation - by more than just the two - in order to get things done - something that having two (apparently) directly-opposed parties hasn't fostered. The two party system has largely fostered only divisiveness and polarization in the populace - as opposed to cooperation to solve the major problems of the day.
Environmental issues are a legitimate concern.
Security is a legitimate concern.
As are the conditions of one's fellow citizens.
And so is corporate greed and malfeasance.
So are the rights of the unborn.
And a whole host of other issues.
Those (on either side) would friviously dismiss the concerns of their fellow citizens - due to having been polarized by a media who often derives it's own power from creating controversy where there is none - are being extremely short-sighted.
The media's modus operandi is largely to take two apparently opposing viewpoints and pit them against one another - the real way to solve problems is being able to consider more than just two viewpoints. Think about it - if you were trying to diagnose an oil leak in your truck, would you only look for it from two places ? .... and then not seeing the leak, decide that there must not be a problem (when you knew there was one) - or a solution for it - simply because you could not see it from the two places you looked ?
I had been a life-long Republican - up until a few years ago. After the "great betrayal" of the last 8 years, I found that I no longer could support those in power in my party. Had, when my party held both Houses and the Executive branch, they had taken effective action to solve the most critical issues of the day - primarily the continuance of a fiat money system, failure to reform government social programs, further deficit spending, and continued growth of the national debt to the point where we are now functionally bankrupt - I might be inclined to support those in power.
But they chose to continue on with the insanity of the operating basis that is "politics in DC".
Since Ohio has semi-open primaries I switched my party affiliation to "independent" which allows me to vote in any of the primary ballots - Rep, Dem, or independent. I'm kinda with Lou Dobbs about sending a message to the two parties - neither one represents the interests of the American people at this point. They only repesent "their" interest to hold onto power. We need to change that "game" ....
Consider registering as a independent (if you are in an open primary state) - or with a third party - it may be the only that we can reform our currently broken system.