Don't click this link yet. Think about all 50 United States, and then, when you're ready, click the link. It goes to an ajaxified quiz page, with a timer set to 10 minutes which starts counting down on page load, and a form entry field where you start typing the names of the states. When you get one right it automatically moves to a spontaneously generating list at to the bottom of the page. If the ten minutes elapse & you fail to name all fifty, the ones that you missed are revealed. Okay, now go.
The Imperial History of the Middle East is a flash based map of the Middle East, with a sliding timeline showing the various forces that have established dominance in the region over the last 5,000 years. Just one of many interesting interactive demonstrations over at Maps Of War.