I try to avoid doing multiple things at once on the computer, since I know that focusing on one thing is when I do my best work (see fighting computer-induced ADD). But I've noticed that I can do two things at once quite well if they're the right two. Two of them are:

1. listening to music
2. reading (but not writing, or much programming, unless the music isn't based on vocals)

That's pretty obvious, but I was suprised by this pair:

1. listening to podcasts, interviews, etc
2. command-line drudgery (upgrades, sysadmin work, etc)

This really suprised me, since I consider the unix command line to be another form of speech. This is making me think I don't really process it that way. Perhaps my mind really considers it a wholey visual/manual activity.

It gets iffy when the sysadmin spills over into minor programming, and once I get into programming where I have to hold a lot of info in my head, I lose track of the audio.