Via the Kelly Lab Blog: Radical Cartography has a terrific set of maps covering a wide variety of unusual topics and visualizations. These are just “thumbnails”; larger versions are available at the site:
Federal land in the US:

Counties named after US Presidents:

How the US would look in the Mercator projection if it were located at different latitudes and longitudes:

… and lots more – browse away!

Good stuff at the intersection of cartography and graphic design. I wonder if any artists work from the other end and make map-themed art?