Of course, there are more than just the two candidates, but voting for someone with no realistic chance to win is tantamount to "wasting your vote", as the conventional thinking goes. But that ignores the reality of the Electoral College (among many, many other things), which renders all but the most competitive states basically meaningless. And a vote can only be "wasted" if it had value to begin with, so to help you determine if casting your vote for The Lesser of Two Evils might make a difference, I put together this handy mapIf your state is not competitive (i.e. is safe R or D) then your vote may have the most impact by, say, voting Libertarian. The bigger the numbers, the more it will make the Establishments stop and think. They won't do anything about it, of course, but the data will empower those not entirely coopted, or who see the opportunity to make a name for themselves as reformers.
Also, if Gary Johnson (the Libertarian Party candidate) gets 5%of the popular vote, the party will qualify for Federal matching funds in the next election cycle. That will be a force multiplier next time around.
This is a very interesting reflection on just how brilliant the Electoral College idea was.