This past weekend I tried out the Caja China, the pig-roasting gadget that's been written about by the NY Times, Saveur, and Jeffrey Steingarten. Got myself a 65-lb pig, injected it with a salt brine the night before, and cooked it according to the Caja's instrux. Sure enough, it came out perfectly in 3.5 hrs (less hthan half the time it'd take on a spit) -- crispy skin, juicy meat. Sensational!
The Caja China comes in three sizes -- I got the middle one, which runs $250 + $50 for shipping. Assembling it took a little over an hour and was pretty simple, although I did have to break out the power drill when a few holes didn't quite line up. It doesn't take up much space but you need to leave a bit of buffer space around it, because cooking the pig takes 42 lbs of charcoal, which gets *very* hot. I accidentally left a plastic trash can too close to the Caja, and it started to melt. But that was the only problem in an otherwise wildly successful pig roast.