My company is throwing away a monster of a machine- an old-skool solder paste inspection machine. http://twitpic.com/mn0tl
Of interest to us is the fact that it comes with an X-Y gantry which is suspended above a frame which could be used to hold a workpiece. The gantry is (probably) powerful and sturdy enough to hold a real, honest-to-goodness milling device. Not a Dremel or Rotozip- a REAL router, or a more powerful motor with better speed control, more torque, and less RPM, for milling metal or other substances.
There's no Z control- we'll have to add that in later. Simple plunge Z (possibly even manual) shouldn't be too hard to add.
The problem is, quite simply, I have NO way to move this thing. It'll take two or three stout men a couple of hours to strip back the parts that are unneeded (there's a sizable chassis associated with it that may not be needed), then wrangle it into a truck (or SUV). We could potentially store it in my garage- although if someone with more space wanted to offer I wouldn't put up much of a fight.