Mackie = Sound on a Stick. They are OK for school pep rallies or the like, but I like the Meyers Mica or L'Acoustic V-DOS for pro systems. (by way of disclaimer, I am a union stagehand, with certs as an A-1 audio tech / board op - among other things)
Back in the day, I had a Klipsch La Scala road system powered by two Mission Cyrus Amps. My neighbors hated me, and they lived about 3/4 of a mile away.
But now I tend just to run the line-out of the iBook into my Crate rehearsal amp - a single 10" speaker. Seems to do alright. I have a Marshall Super Lead Plexi (not the replica, the original) that when I refurbished it I ran a line-in but that seems extreme for the apartment ya know. I do break down every now and then and put on some AC/DC and let it rock.
But mostly I listen on a Samsung MP3 player with a set of Grado SR325 headphones. That seems OK too. The MP3 lack the sonic imaging of a CD player, but the size deal is huge. For what my Samsung can carry in it I would have to pack a huge amount of CDs.
And, I'm either going or coming from a show, and I've long since given up on getting anything to match the sound of a good line array system, so I listen close when I'm at the show, and get by the rest of the time.
kat