Yahoo maps and their ilk are a useful resource, but not too effective when you want to walk or bike to a place. They provide little idea of how cultural attractions, transit stops, or bike parking integrate with the street network. There is a global project to build maps that do this - the Greenmap project. Chicago's Greenmap has a head start and has a few maps already out there - well known neighborhoods such as Chinatown, Wicker Park, and Rogers Park (which is incorrectly linked on the site).