If you are considering not voting for president, or voting for a mini-candidate, consider this:
In 2000 Al Gore had 50,999,897 votes, 48.4% of the total.
Dubya had 50,456,002 votes, 47.9% of the total.
Dubya won 271 electoral votes, compared to 266 for Gore, and became POTUS with help from the SCOTUS. Ultimately, he won by _one_ vote, in the Court.
Green Party candidate Ralph Nader won 2,882,955 popular votes, 2.74% of the national total, and no electoral votes.
In Florida (25 electoral votes), there were 2,912,790 votes for Dubya, 2,912,253 for Gore, 97,488 for Nader and 38,298 more for other minority candidates.
The tiny difference of 537 votes between Dubya and Gore could have been easily beaten if fewer votes went to candidates who had no chance of winning. Or if more people decided to vote, and voted for Gore.
The world might be very different today without Nader, Buchanan, Browne, Phillips and others competing in Florida.