You haven't seen the Stack overflow calendar yet?
Today while on my SO profile page , I accidentally clicked on their "visited" statistics. (They have a few badges for people who come to the site regularly like 'for n consecutive days' and so on) And then to my surprise I found a neat calendar view of all the days. Though not very useful or anything. It was kinda cool and surprising to see how much my life/career has become dependent on stackoverflow.com