Not really an Android tablet question, per se, but relevant from perspective of accessories. I only learned of the concept of vibration speakers today. A vibration speaker sits on another surface, and apparently uses the resonance of the surface to sort of make the surface become part of the speaker. Is anyone using one of these things? Is the sound quality any good? Do any of them support true stereo? Mods - if this is in the wrong place please move it, though I didn't see a good place to ask about accessories.