What are my compact CNC milling machine options for stone carving?
There are a bunch site like hobbycnc that sell plans and parts to build your own hobby cnc.  Here's a site that sells a kit.  Looks pretty neat actually...now I know what I want for Christmas!

Update:
Just found the Torchmate series.  They have a Torchmate 2x2 version starting at $3000.