Vibe-Tribe - Troll Mini Yale Blue: the Ultracompact Vibration Speaker, 3 Watt, with Bluetooth and Hands Free.

I had a resonance speaker from a different company but it broke, so I bought this one from Vibe-Tribe. I use resonance speakers for the novelty, not to actually listen to music. I enjoy testing them on different surfaces to hear the differences in sound. They work great as a party trick - have people try putting them on their skull, it's quite a trip! Unfortunately, this one is just not big enough to be useful. No matter what surface I put it on, it wasn't loud and didn't make a satisfactory vibration. Buy a bigger one with more power.

This little Bluetooth speaker packs a powerful punch. I was part of the initial crowdfunding campaign and I was so impressed that I purchased another one when it hit the mass Market. This thing will blow you away once it's connected and attached to a surface.