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The October issue has an article on washer/dryers but doesn't mention practical criteria like vibration. A few years ago I came up with an inexpensive and simple way to damp out vibration, based on acoustic physics. Basically, sound will reflect when it encounters a large difference in density. If you combine a density gap with an absorbing layer, most of the vibration is eliminated.
The technique can be found here : http://www.genuineideas.com/HallofInvent...
All you need is a plastic welcome mat, some construction adhesive, and a sheet of plywood. Let me know if it works for you.