Rentometer is there to let you know just how much your rent compares with the rest of the neighborhood. Just enter in your address-no personal information is saved, so no worries there-and how much you pay, and the site will let you know if you're paying more, less, or the average for your area, with a handy Google Map of logged rents, so you know just what doors to go knocking on to try to score that rent-controlled place of your dreams.