Recently, I've been playing with Riemann, and today I added a few new things to my dashboard: a simple gauge that tells me the length of my playlist, and a time series chart on the playlist length + average song length. This is useful to me in a number of ways:

• I often forgot to turn music on, and just sat there with headphones off. Now I get a warning on the dashboard if I do so.
• The length of the playlist is a good indicator on how much time I spent being so immersed in something that I didn't notice the time again.
• It looks damned cool.

Will publish my scripts this weekend, if all goes well.