See it in action http://www.youtube.com/watch?v=jcyL4Q-zxrg
You need 4 8mm ball bearings (or similar, maybe even marbles) to use these.
This is a 3 part vibration isolator. It consists of a top ball isolator. It allows the machine to move in all directions reducing the lateral movement transfered to the table. It needs a 8mm ball bearing.
The bottom part is a spring that reduces any other vibrations that get past the ball isolator. It also has holders for a coil spring to take some of the weight of a heavier machine.
I have also noticed since using these my registration has been better as the whole machine moves rather than the frame flexing. It is also much quiter then before.
It may look a bit unstable but I have been unable to topple mine yet, even giving the machine a hard shove.
The smaller part of the ball isolator sits on top of the spring (a bit of glue is helpful here). Then the ball bearing, then the other part of the ball isolator. The machine then sits in the dips. Again a bit of glue helps here.