At the moment I have my monitors on a raised platform that is part of my desk. They sit on Mopads which rest on the desk. I'm not sure how much vibration the Mopads prevent, to be honest; I know they still pass a lot on.
I've been looking at china cones, but I know they take the opposite approach. Rather than decoupling the monitors, they actually couple the monitors to the surface, passing on a lot of vibration, but supposedly at non-audible frequencies. The advantage should be that the monitors are absolutely locked in place, and thus don't lose energy in moving themselves. I'm guessing, though, that the cones are only going to give any improvement when used on a surface that doesn't resonate much itself...which isn't my desk. I suspect that, when the cones pass on non-audible frequencies, my desk is going to vibrate at a whole bunch of harmonics.
Is anyone else using them, and what has your experience been?