lastgraph
Lastgraph is a free service created by Andrew Godwin that generates beautiful histographs of your last.fm music history. I just recently rediscovered it and, having been jealous of Lee Byron’s personal graphs for around a year, I thought I would give it a shot.
I entered my username, a date range (Dec 05 to Dec 07), and my email address (optional, used for notification) and within minutes I had an email (actually, for reasons unknown to me, I had two) linking me to this beautiful graph. Apart from the service being free and fast, the rendering is gorgeous. Lovers of music and stats (or either) should really give it a shot. Of course, you will need a Last.fm account with a worthy amount of information first.