only 12" wide
The biggest problem I've encountered is finding the stuff to make it with. If I just had to design on paper and have the thing fabricated, it would be a piece of cake. But fabrication costs as much as that 50" plasma screen. It's completely out of the question.
My only option is Home Depot or Lowe's. If they don't have the raw materials, I'm up the creek. You might think that I could just buy the thing that I want but ... no ... it isn't available. You can't buy a boom to mount your TV on to watch in bed. You can only mount it so that the TV is between you and the wall. I want me to be between the TV and the wall. Get it? It ain't to be found and there is a good reason for it not to be available. For if you could buy such a thing, the bedroom large screen TV market would dry up instantly. Why pay thousands for what you can get for hundreds?
Why this will work
You probably watch your computer from about two feet away. If you have a 17 inch monitor, the width of the screen is about 13 inches. So at four feet away you would have to have a monitor twice that size to achieve the same effect, i.e. 26" inches. At 8 feet away you'd need a 52" monitor at the same resolution to see the same thing. And here is your large screen LCD TV. A 52" LCD costs thousands of dollars while the equivalent 17" monitor at two feet will cost you only a few hundred bucks. I priced a Samsung in Best Buy with 1280x768 pixel resolution at 12 milliseconds and it was on sale at $359. Of course, that doesn't include the TV guts. To get that I found the Viewsonic box that you hook up to any computer monitor to show TV, audio, DVD, VHS, etc. It costs only $129 but services only 1024x768 resolution. Presumably it would be OK on the 1280 as well but you'd be wasting some resolution capacity. I have as yet been unable to find the 16/9 form factor I would prefer to use. I'm still looking and in no great hurry.
The only real difference between a large TV far away and a small screen near is the strain of focusing your eyes on the closer distance. But most people have no trouble with this at computer distances for hours at a time so I see no problem here for movie watching which takes no more than maybe 3 hours at most.
One thing I am sure of ... 640x480 resolution is out of the question for the picture I want to see. 640x480=307,200 pixels. While 1024x768=786,432. This is over two and a half times greater resolution than the 640 screen. I tried out different resolutions on my 17" CRT and found little apparent difference between 1024 and 1280 and "The Day After Tomorrow" and "VonHelsing" looked great at either resolution. So I may settle for the 1024 just to use the cheap Viewsonic TV converter. Then, I'd need a DVD but DVD players are now like dirt ... $39 still plays well enough for me. And then there's the speakers but presumably you'd be using quality headphones anyway so my unused leftover HP stock speakers will do for this setup (if I can find them in my computer junk box on the porch).
Also, one might go to the 19" monitor but I once had one and found myself spontaneously moving farther away from the screen. So I went back to the 17" monitor to same money when the 19 fizzled. I think there is some optimum screen size for close work and it appears to be about 17 inches. Of course, if you want to open several applications simultaneously, you might want a giant 21 incher. There is a good reason why books are about 17 inches from corner to kiddy-corner. If there is too much information presented to us at once, it looks too busy and we seek to tune some of it out in order to achieve an easier mental focus. For total immersion (like IMAX) you'd want a bigger screen but also much greater resolution. Much more than is currently offered even in big TVs ... someday ... maybe ... whole wall TVs. But it'll be some time yet so don't hold your breath. And they'll still use a 17" monitor for close work anyway.
The Benefits and Drawbacks
First it of course, the lower cost. Another is the ability to fall asleep right there in bed while the DVD finishes up by itself. No problems here. There is also a "cuddle factor" if you are with your significant other. Both have to get near the center line of the monitor. Also, you free up some wall space by removing the old TV and stand.
The drawback is that the small screen is no good for your living room where you want to have several guests in to watch football or a movie. You really need the big TV there. Another drawback is that you must build your own setup 'cause they (the TV manufacturer's) don't want to lose big dollar sales in the bedroom which would be inevitable.
Present working model
I've tried designing from the components I find in Home Depot. There are steel pipes for water or cool looking black pipes for gas (these are pretty heavy and ... I just realized last night that you can't form a closed pipe loop because you must loosen one of the threads to tighten the other).
There are cool looking conduit parts (these aren't meant to be structurally significant but my strength requirements aren't too heavy. However, because the metal is fairly thin, they can't be threaded so they make available cast aluminum connectors where one end is threaded and the other goes over a pipe end and is held in place by a set screw. This isn't too cool because based on my life's experience, a screw will come loose and my LCD will fall on my head sooner or later).
There are PVC pipes and connectors. Easy to work with but ugly and cheap looking and ... they bend under load if not big enough.
Then there is the everpresent wood (which I find to be aesthetically "out" and so it's too ugly to use although easy to work with).
There is also the possibility of a hybrid ... metal, wood, plastic boom as well. I will add to this page as the thing develops or fails.