I hate the term third party, it lumps all the parties that are not Republicans or Democrats in one group. However, it is a term people understand until we make a choice as American's to support more than
one party two parties. None the less, NPR had a piece about what is happening outside of the "major" parties.
In this piece they talk about Cynthia McKinney, Ralph Nader and Michael Bloomberg. They also talk about the possibility of Ron Paul running as a 3rd party candidate.