The people who say you can't do it are *dead wrong*. I'm sorry, but it's true. I'm presently aging my Christmas roast right now. Same process I've used for the last 8 years or so.
How I do it is simple. I went out and bought a tupperware cake container. I don't know what to call it specifically. But it's 2 pieces. A flat plastic bottom and then a plastic dome that can clamp onto the platter underneath.
Then, I pulled out my drill and a 3/4" drill bit and I drilled a bunch of holes in the dome (for promotion of air flow).
I used some lifters on the platter, and then put the prime rib in there so that it's not touching the bottom. Then you take a tea towel and put it under the rib roast, and place a paper towel over the top. Paper towel gets replaced daily.
Attach dome. Throw it in the fridge for at least 1 day, up to 5. I wouldn't go much more than 5, but that's just cause I hate to think of possibly ruining a hundred dollar piece of meat. After 5 days, trim off any leathery parts, and cook away.
Is it professional dry aging? Absolutely not. But it makes a ton of difference in terms of the quality of the roast and is absolutely safe and proper.
Edit: Just went to the fridge to look at the apparatus. It's made by Sterilite. Doesn't say specifically what it's called but it's meant for hauling cakes. All said and told I think I paid like 7 bucks for it, and it's served me well for almost a decade now (though obviously aging is all it's used for)
Edit Edit: Found it online:
http://www.housewaresandbeyond.com/p12906-Sterilite-0200-Cake-Server--White.html . They cost 12 bucks now these days I guess :P.