You have to see this. It’s a panorama of St. Peter’s Square that has been rendered into an interactive using QuickTime. It may take a moment to load if you don’t have a fast connection, but I think it’s well worth the wait.
After it loads you can use your mouse to move your perspective. Just click anywhere on the screen, hold your left button and move your mouse around. You’ll get the hang of it. They even caught a bird flying overhead.