http://www.flickr.com/explore/

On any given hit, you get 8 of the most amazing photos you've ever seen, and more links to others. I'll warn in advance ... I've found this page to be highly addictive. Whether I am looking at the calendar mode, checking out interesting sets, exploring the photo groups, or even seeing interesting photos from the last 7 days I've often spent more time than I should going through these images, lol. There's some amazing stuff out there