OCIA.net checks out some Vantec Vibration Dampeners in their latest review! Here's a snip.

"The fan kit comes with two 80mm silica gel vibration dampeners, more than enough fan screws to install two fans and silica gel washers to use if the fan dampeners will not fit your case situation. The dampeners are easy to install. To use them, simply place the dampener on the fan on the surface between the fan and the installation point and screw the fan in place."