There's two primary sets of stereo monitors in my suite and a tiny mono speaker in the meter bridge of the Studer. Between those three I rarely need to take a mix outside. The last time I can even remember doing that was a couple years ago when I switched the Dynaudios, and that was just the first song while we drove up the street for some grub. When we got back I mixed the rest of songs without checking them outside the room.
Beyond that, there's headphones and a set of Altec Lansing computer speakers attached to the office computer. I don't really *check* mixes on 'em, but I will listen to the mix on them before I upload it for my clients. The DAW isn't connected to the net so I transfer stuff between the machines with a USB memory stick which is quick, dirty and oh so cheap.
But really it just comes from experience. When you've been mixing for 5 or 10 years you don't have to second guess stuff all the time. It's like playing an instrument, riding a bike or anything else. Time & practice lead to experience and excellent execution.
As for the dead CD's...AFAIK they can't be recycled but I still toss 'em in there. I also have a couple hundred (a fair amount were promo & AOL CD's) that I'll turn into an art project one of these days. These guys are pretty cool & might give you some ideas;
http://www.nomoreaolcds.com and there's always the option of a CD shreader.