Holy cow. I will never be bored again. I just discovered RefDesk.com. Daily photos of many kinds, words and quotes of the day, online literature links, news links, game and brain-teaser links, reference materials of all imaginable varieties, and just-for-fun links such as the diary of Samuel Pepys, the Shakespearean Insultor, and the Oxymoron List.
It has already led me to add one RSS feed to my friends list: googlesights, a couple daily satellite photos of various places in the world, and a description of their significance.