I actually led the charge on my site PivotAmerica.com to encourage people to go green/vote for Jill, but I don't really think it's possible to break up the two party monopolies anytime soon, and her opinions on vaccines, and nuclear energy are disconcerting.
A nuclear power plant is NOT the same thing as a weapon of mass destruction. And you can't just print money like she wants to do for the education plan - Bernie's plan of raising taxes on speculation makes way more sense. But I did throw my vote to down-candidate dems. But Hillary ran the shadiest campaign I've ever seen, and is one of the most corrupt people in the world. I'd say she's worst than Bush / Cheney imho, or at least not far removed in policy. (THey both supported the Iraq war after all).
There is no perfect candidate other than perhaps yourself. When it comes to third party, you can safely consider your vote a vote for the party values themselves, rather than the candidate in particular. A vote for Jill Stein is really a vote for the major political parties to work on more green legislation.