This pic above, is so synonymous with Windows. It's not as famous as the Mona Lisa, but it could very well be the most viewed photo of all time. This is Charles O'Rear's Bliss photo.

Published in 2002, the photo got most of its distribution as the default desktop wallpaper for Microsoft’s Windows XP’s “Luna” theme. O’Rear, a former National Geographic staffer, snapped the photo while he was on break from another assignment in California’s Napa Valley.

O'Rear didn't disclose how much Microsoft paid for the photo, but O'Rear said it was "extraordinary".

Just how many people do you think have seen that photo?