Sometimes I do other stuff while I'm online and just have stuff in my ear in the background. Lengthy, complex or jazzy type stuff has been good for that lately.
I always enjoy hearing my favorite stuff in the car too. Don't generally like hearing new or stuff I haven't heard before in the car unless its an artist i really love, but it depends on my mood.
I never listen to stuff out and about though. I don't do the ear buds out at all anymore, although on some occasions if I'm walking by myself or something it could be appropriate. I generally just don't bother with music if I'm really busy, as much as I love it.