If you are a regular iPod user, you might be interested in this software, which allows you (and your friends) to view your listening habits on line. When you syncronise your iPod, the tunes that you have recently listened to simply get uploaded onto a personalised web site. From there, you can view your most listened to tunes and even create your own charts! I am totally hooked. The great thing is that it will either work if you listen in iTunes or if you listen "on the go" - on your iPod away from your computer.
There are PC and Mac versions available and it will also work with the Shuffle, Motorola iTunes phone and presumably the iPod Nano.
Take a minute to visit the Last.Fm home page for more information.
You will notice that my recently listened to songs are in a panel on the right of this blog -->
Have fun!