A few weeks ago I started a project called SCHWARZPLAN.eu, a german web shop for figure ground plans of different cities all over the world. Thanks to OpenStreetMap.org there is a nice possibility to use the vector data for all buildings, that are drawn and export them to different file formats. At the moment the figure ground plans are downloadable as PDF-files because they can be handled the best way and have less file size.

At the moment the most plans are from German cities. That's because many other cities haven't all building-information vectorized.