If not an electrical link between controller and arm then it would have to be radio controlled with some kind of onboard computer. Let me try picturing this. you want a 3 pivot arm (sort of like what they use to spot weld car bodies together at the assembly plants) being controlled by someone thru a computer. With the ability to record the movements made and be able to repeat them. Only on a smaller scale?
At my work, the computer geeks use this thing called a gyro mouse. They use it to move the cursor from screen to screen to screen. Imagine one computer, numerous screens and the ability to pull up any menu on any screen independantly or seperatly or all together, wierd. As I understand it, the gyro mouse creates a 3 axis grid in space. Now what if the "operator" had a similar device in their hand relaying positioning information back to the computer to drive the arm thru a wireless LAN link (ok, now we're up to 2 computers).
As for the arm mechanics, that's easy.
If it's not nailed down, it's mine.
If I can pry it loose, it's not nailed down.