VotersUnite! has a database of election problems, including a machine-malfunction category. Our very own Sarpy county in Nebraska had 3000 phantom votes. That error was found and corrected; imagine the impact of all the other likely machine problems that are yet undetected.
Other sites to visit once or many times:
http://www.blackboxvoting.com/
http://www.blackboxvoting.org/
http://www.votergate.tv/
I recommend remaining skeptical of our reported election results, of the theories of vote-challengers, and the claims of vote-defenders. Just the facts, ma'am.