Available for iPhone, Android and Windows Phone--an idiotproof way of unsubscribing from junk mail. Upon downloading the app and entering your address, all you have to do is snap pictures of the magazines, catalogs, credit card offers, etc., that you no longer want to receive.
PaperKarma will then contact the offending company to get you off the mailing list and send you a message when you've been successfully removed. (We heard back from them within 24 hours.)