Over at Boston.com, there is a section called The Big Picture, which, as the name suggests, features on a regular basis, really big and high resolution pictures of various topics, each topic containing a dozen or two pictures, to give exquisite details to the subject matter. To give you a taste of what they are all about, some of their former contents were: Green Sahara, The International Space Station turns 10, Peering into the micro world (highly recommended), Enceladus up close, The Sun, Hurricanes as seen from orbit, Preparing to rescue Hubble and many more. Although my choices were largely of spatial nature, other categories range from sports to politics to pretty much anything. There are even recent scenes from North Korea.
And now, for the grand finale to celebrate the end of 2008 they put 25 Big Pictures of the Cosmos taken by the Hubble Space Telescope, in all their glory, to form an advent calender. Simply breathtaking images. You can (and should) check them out here.