we started with cl-prevalence and then of course (NIH-syndrome) implemented our own approach to this back in 2003, which you can find at http://bknr.net/ . We used it back then to run eboy.com, and it still is powering http://quickhoney.com http://www.createrainforest.org/ and http://ruinwesen.com/ amongst others. Those transaction logs + images are for some 6+ years old, and have gone through multiple code rewrites and compiler changes and OS changes and what not. It is good fun, has drawbacks, has advantages, definitely widens your horizon.