While many of us are familiar with the Wikipedia project, there is a similar and related project to gather non-copyright or open copyright media on subject matter. There is a Geography category that has video and images that are fairly general, many of them human/cultural geography related. There is a Map category that, of course, has maps of different types. And, there is a Cartography category, that is a mix of maps and technical explanations including explanatory images of projections.
You can also search keywords to find interesting images that have been placed in other categories.
I agree, this is a great project. The Wikimedia Commons reached 400,000 files! Here’s the original slashdot article: http://slashdot.org/article.pl?sid=06/01/22/1441228 also, slashgeo provided two weeks ago additional links to UN maps and http://www.lib.utexas.edu/maps which may be of interest: http://industry.slashgeo.org/article.pl?sid=06/01/24/1513258