Photographer David Bergman took the wide-angle photo above of President Obama's inauguration. It's nice, but doesn't look terribly impressive--until you learn this single image is actually composed of 220 individual close-up pictures. What that means is that you can zoom waaaaaaaay in on any part of the image. Pick out all the ex-Presidents and dignitaries sitting behind the podium. Catch a guy in the Marine Corps band napping. Find Aretha Franklin's hat. Pick a spot far, far back in the crowd and make out individual faces. If you were there that day, you could probably find yourself in this picture.
It's quite a contrast to this photo of Lincoln's inauguration, which I believe was the first one ever photographed. Bergman's "gigapan" image, as it's called, is a genuine contribution to history.
Go here to see the big picture when you've got some time to kill. Be patient while it loads; I can almost guarantee you'll find it worth the wait..