milling an smd pcb is quite difficult...
my first attempts to mill the openservo pcb were not so good. The pads where too small. So i have created a program that strokes each pad until it reaches an other path and then leaves only one pixel between them. You just have to create a black/white 24b bitmap of a pdf with photoshop or an other application and load it into my program.
This is the result:
http://www.basicfox.com/Top-Big.gif (Top layer of V2 Openservo PCB)
http://www.basicfox.com/Top-Big-Routed.gif (New Bitmap after 40px stroke)

Specify a zigzag direction if your cnc has backlash on one of its axes (like mine does)
After that u can save it as a .tap G-code file and load it into your cnc milling software.

You also can drill the holes automaticly:
http://www.basicfox.com/Holes-Big.gif (Holes of V2 Openservo PCB)
http://www.basicfox.com/Holes-Big-Routed.gif (after you saved the G-code)
The program searches for the middle of each black dot and then only marks the middle of it.

If you are interested, you can download the program here:
http://www.basicfox.com/BitmapnaarG-code.exe
it requires the .net framework