Brad Thompson has just released Pastmapper, a new platform for describing the past. With Pastmapper, users can see mapping of the past in a contemporary context as well as understand about the past in a contemporary context.

Currently, Pastmapper shows San Francisco in 1852-1853, in a Google Maps style, with geocoded directory listings for businesses and individuals. In addition to this every increasing wealth of information, you can see the historical coastline of San Francisco, building footprints, and streets in the city that eithe r no longer exist or have changed name like DuPont Street.

Check Pastmapper frequently as this is the v. 0.1 release and it's sure to grow quickly.