Chicago Bicycle Routes - Here is a pretty involved Google Maps mashup showing you bike routes in Chicago. The map key shows lanes, off-street trails and recommended routes. Be patient with this one as it takes some time for all the lines to draw out.
Edinburgh, UK: Google Maps property search - This is a Google Local UK mashup that places up-to-date properties for sale in and around Edinburgh on Google Maps. The creator mentions to me that the mashup itself is not particularly original but geocoding is harder in the UK than the US as the UK lacks a tool similar to geocoder.us.
RoadPetition.com tries to put an end to traffic lights using Google Maps - From the site: "The average American spends 6 months during their life sitting at a red light" Are you sick of looking at a green light shining down on an empty roadway? Could your commute improve drastically with a simple motion sensor? Do something about it!! Use this site to find that annoying traffic light and make people aware of the problem! Create a petition or sign one if it exists. Leave a comment or just rate the intersection. Together we can spend more of our life at our destination! [via]