SurveyGizmo for iPhone lets you create and participate in polls about anything under the sun. Match up your votes with other users about the next president of the U.S., where we go when we die, whether you're a dog or a cat person, and other funny and interesting poll questions. Results turn up in a pie graph for easy viewing.
iPhone Link: http://mobile.surveygizmo.com/
Web site link http://www.surveygizmo.com/