"The U.S. Geological Survey has just released more than 161,000 digitally scanned historical maps spanning in excess of 130 years and covering the lower 48 states. This Historical Topographic Map Collection provides a comprehensive repository of the landscape of our Nation..."
Family Tree of the Greek Gods is a site using a visual organizer (now in beta) called Spicy Nodes. They call it a "natural and inviting" way to present information in "nuggets" that move in virtual space as you view them one by one. Another example: Daylight Savings Time.