Have interest in history and maps? Love the open source content? Love Google maps, Google street view, Google satellite, Google Earth and all other such things that allow you to experience the world from the comfort of your computer?
Here is good news for you, new addition to the open source database.
New York Public Library have made available its digital map collection under the Creative Commons license, so you can download 20,000 digitized, high-resolution, historical maps, some even as old as 1600. All this you can download for free and do whatever you like with them.
Here is the news article which explains you how to use and access these maps. Go through this article and a video to get the clear understanding of what can be possible with these maps.