According to people who study this sort of thing, there is a 1 in 200 chance that McCain and Obama will end up in a 269-269 tie in the electoral college.
That could create some interesting scenarios, including having Nancy Pelosi serve as President for a while...
Not likely, but funny to think about the circus that might happen.
http://www.abcnews.go.com/Politics/V...5386278&page=2