I really love to look for anachronistic little things around my city. (I adore Forgotten New York for this reason.)
One thing I keep my eye out for is boot scrapers. These are little flat pieces of metal either imbedded in the steps of old houses or welded between the banisters of the railings that run up the stairs. These are relics of when transport was by horse and carriage, so there was quite a lot of manure on the streets that you wanted to scrape off your boots before you walked into someone's house.
Two of the houses on my block have bootscrapers still.
