Really old maps online by Nathan Yau.
From the post:
Maps have been around for a long time, but you might not know it looking online. It can be hard to find them. Old Maps Online, a project by The Great Britain Historical GIS Project and Klokan Technologies GmbH, Switzerland, is a catalog of just that.
I do wonder when the organization of information in its various forms will be recognized as maps? Or for that matter, visualized as maps?