I've been blogging since November, 2001 and began in earnest in Februrary, 2003 thanks to Blosxom. Below is a calendar-based visualization of the days I posted:
Each day is a square; brighter squares mean more posts. The code to generate these graphs is available but it sure ain't pretty — I hacked it out as fast as I could with only some simple unit tests to keep me honest.
  2004-04-11 00:51 Z