Here is what I did after a crash broke my VGE mount.
[youtube]http://www.youtube.com/watch?v=xkCVKy6odto[/youtube]
It does much better at full speed but I did notice some more jello later on at slower speeds. Maybe the foam compressed too much so this may only work short term very well. Another way a friend of mine stiffened his anti jello mount is using some small orings to compress the rubber balls a bit more. You could possibly just use some rubber bands around the mount which would help compress it a bit but not transfer any vibrations through to the mount.
I will try a few things as I have another mount coming with my FPV setup but DHL express sucks so bad. It took less then 12hrs to get from Hong Kong to Melbourne from purchase and its been 4 days since and it hasnt made the last 30km yet :x . Apparently its on a vehicle for delivery now and luckily I have a day off, so fingers crossed it does make it. Maybe this mount will be stiffer then the original one I had but if not I should be able to mod it as I intend to do a bit of high speed FPV once I get used to it.