Real News hosts a debate on the left blogged earlier here about "strategic voting"-- i.e. whether 3rd party/left supporters should vote for Obama in a swing state. Arguing for "strategic voting" ("yes, vote for Obama in a swing state") is Jeff Cohen of rootsaction.org; arguing for straight-up 3rd party voting whatever your state (and in this case, for the Green Party) is Cheri Honkola, long time poverty activist and vice presidential candidate on the Green Party ticket with Jill Stein.
Here is a New York Times electoral map showing Obama currently with 237 needing 33 electoral votes to win, and Romney with 206 needing 64. Toss-ups include Nevada, Colorado, Iowa, Wisconsin, Ohio, Virginia, Florida, and New Hampshire.
I googled briefly to see if there was any comparable debate on the right, and at a quick glance, found this article on behalf of libertarians voting for Romney, and this article on behalf of libertarians not voting for (lesser of two evils) Romney, and this article challenging Romney to prove himself to libertarians tonight.
Tonight, the two mainstream candidates debate foreign policy. (I gather Democracy Now! will host an expanded debate, as before.)
Tomorrow, the Free and Equal Elections Foundation (which looks mostly libertarian funded) hosts 3rd party candidates debating on the left and right, including Jill Stein and Rocky Anderson. 3rd party/right would be Gary Johnson and Virgil Goode.