Years ago in some home I saw someone whose stereo equipment rack was on an exterior wall (or exterior to the attic at least). The rear of the rack was then easily reachable by going into the attic and opening a small panel door that was installed on the backside of this rack. Given how difficult it is to plug in the countless wires in the back of any modern AV receiver, the genius in this is not hard to see.
So when it came time to build our home, which included a media room, I knew this was the way I wanted to go. Of course, I did a bit more research. AVS Forum has tons of great ideas on how to set up an equipment rack (as well as what kind to use). I also knew that with the structured wiring setup I was going to have, it would be wise to have these all in the same place. There was an appropriate space in our floor plan to add a long 'closet' along one side of the media room. This was to be the location of all of the equipment. The hardest part here was communicating clearly to the builder how the rack had to be framed in. I was going to use a freestanding rack which would stand flush to the wall in the media room, but extend into the equipment closet where I could install/remove equipment with ease. I decided on a Middle Atlantic Slim-5 rack, and asked them to frame a hole in the wall with the same dimensions as the rack (actually a touch bigger to ensure it would fit, and the gaps would be covered with trim material). Also, because there was a riser in the back of the media room (where the rack would be), a similar riser had to be built in the equipment closet to accommodate this (actually, it had to be a bit higher since the rack was going to set several inches off of the media room floor). It took about 3 attempts before they correctly framed what I needed, but it got done!
The Slim-5 rack comes unassembled, but assembly is relatively straightforward. This rack effectively has no shelves. Some equipment is designed to be rackmounted directly using either included or optionally available rack mount 'ears'. These ears are attached directly to the front face of the rack supporting the equipment in a cantilevered fashion. Sounds shaky, but is incredibly stable in practice. For equipment that does not have the ability to be rackmounted directly, Middle Atlantic sells an assortment of shelves, drawers, blank panels and other accessories to fit into the rack. The best thing though, is that Middle Atlantic also sells custom cut faceplates for their shelves that are cut to the exact dimensions of the equipment you have. Their site has templates for the make and model of almost everything (everything I needed at least) including things with odd shapes like an XBox360. Using these left the entire rack with a 'finished' look that looks fantastic in the media room.
On the backside of the rack, I used a bunch of lacing bars that Middle Atlantic sells to organize the wiring. These things are almost a MUST if you decide to install a rack like this. The whole idea is to keep things neat, organized and accessible, which the lacing bars do perfectly. Plus they're pretty cheap. I think it was under $20 for a pack of 10 or 12 of them.