When I was setting up my theatre, I chose to put all electronics in the adjacent mechanical room, but couldn't (and didn't want to) expose them in the theatre because I couldn't get at the common wall due to all the mechanical equipment occupying that space.
So since I didn't want to expose it through the hallway wall near the theatre, that left me with a simple option. Knowing I'd eventually move (this isn't my dreamhouse) and probably build another HT, I wanted something that would be freestanding, look good, be adjustable, and moveable. I ended up building a rack out of birch plywood, with a tiger maple face frame, a fixed shelf halfway up, and then five adjustable shelves. I used dado construction, and left it natural with a satin polyurethane finish. It is 74" high, 22" deep, and has adjustable legs underneath.
It looks and works great, although few people see it unless I'm showing it off. I've got my HTPC, and a NAS server and monitor in it, followed by my Pio Elite 74 TXVi with Beheringer FBQ2496, a Toshiba XA2, a Denon DVD 1920, a Samsung HD receiver, and my networking gear (16 port Netgear gigabit switch, a wireless router, and the DSL modem), and some left over space waiting for a Bell ExpressVu 9200 HD/DVR. Check it out (looking through the door to the mechanical room):
On the back view, you can see 3.5" wide pieces of plywood that will hold vertical power bars and the cable management system that I will install, once I get the HD DVR up and running and route cables to my rear speakers.
Finally, one last thing I want to do is replace the CRT monitor with a smaller LCD panel to make better use of the rack space. With this setup, I don't have to worry about fan noise or cooling, since I can just close the door on it!