A little bit of scotch, low lights and nothing else but the music is simply awesome. 

Someone added scotch to the thread... Cee Tee should be here any minute now! 

Depends.
But I do find it exremely satisfying to listen very intently.
Not too sure why, but when I listen to vinyl, I do nothing but sit and listen uber intently.
Maybe it's the whole convenience thing, but I can listen to CDs either ultra intently or as background when I'm surfing or cleaning.
I normally listen to music (iPod or CD) when driving but I never feel like I'm actually listening intently.......too busy driving I guess.  But I can still easily be drawn into the music.

As a more serious listener I sometimes prefer easy listening Pop, Disco and Jazz.

Thing is, when a song or track just hits you, you listen and everything else becomes less important. I sometimes write album reviews and while listening I read articles and make notes. Sometimes a song or track makes me stop doing anything else.

A track as simple as Clyde Stubblefield's break beat and James Brown's fascinating vocals on "Funky Drummer" awaken my inner B-Boy and fuck everything else. Right now Willie Hutch's "Brother's Gonna Work It Out" made me pause before finishing this sentence. Music...

It all depends. I used to listen to music all the time in my '95 Civic, which I put a decent DIY stereo into. Anytime I drove anywhere, I'd crank up the music and enjoy myself. Now that I rarely drive (I literally live across the street from where I work and live too far on the north side of the Springs to get out often, plus third shift life...) and have a newer car without quite as fun as a sound system, that doesn't happen as much.

With my stereo setups at home, they're mainly used for computers, gaming, TV, etc. TBH, maybe a couple hours worth of music at most goes through them in a month or so.

I can't have music going on in the background when trying to get work done (household stuff doesn't count). I just get too distracted. Other forms of noise are OK, like a TV in the background, but I can't do music even at low volumes.

On my weekends, I usually spend about 1-2 hours a night/day just listening to music if I have nothing else to do or am browsing the toobs. If I have new gear in or am modding something, I spend more time doing listening tests than kicking back and enjoying the music.

I tend to have difficulties focusing on music with even a mild alcohol buzz (as much as I do like a bit of alcohol...or more sometimes), but I have another substance of choice that I enjoy combining with music (Colorado, if that tips you off). I tend to listen somewhere in between casually and with concentration, though it varies on what's playing, what I'm doing at the same time (if anything), etc. Obviously when I'm doing listening tests, it's more concentrated.

I would probably listen to music more if I didn't find so many headphones uncomfortable after an hour or so, that and finding something that doesn't fatigue my ears. Can't produce too much noise either since everyone else is asleep while I'm awake (this will probably be the case for another 1 to 2 years or so).