I use iChat every day, and I use its custom status messages quite extensively. You can select from preset available (green) or away (red) statuses, or easily create new ones. From my usual green "Home Office" or "Home Office, on a call" to a red "back this evening", I try to provide useful messages. It's pretty great.
Nobody needs to know *exactly* what I'm doing 24/7, so sometimes the most useful thing I care to share is what I'm listening to on iTunes. That's actually a non-editable preset status in iChat, but only as an available (green) status. Not anymore! After a bit of googling, I found this great method where you use the Edit Status Menu... option at the end of the status selection list in iChat and use the below screen to create a new custom away status of "%Title - %Artist", like so:
...and then you can have great away statuses like this one:
One note before you use either the stock or custom iTunes methods: scrub your library of curseword-laden titles unless your employee handbook is really, really generous. I have a lot of asterisks and underscores in titles to avoid having to remember to always start iTunes from a custom smart playlist that avoids certain tracks.
Anyway. Fun!