You may have heard of subwoofers, which provide very low-level bass frequencies. Tactile transducer go beyond that range because they vibrate solid objects rather than air.
The Buttkicker uses a “suspended magnetic system” to reproduce soundwaves that are not air dependent, and can reproduce frequencies down to 5HZ (below human hearing). Variations of the Buttkicker are found in professional settings, such as movie theaters, and concert halls. The Buttkicker 2 came out recently, they cost around $250.
Clark Synthesis Tactile Transducers have a very compact transducer design, and can be placed inside (or on the bottom of) chairs, couches to produce deep bass response that is both intimate and effective. They also cost around $250, and are available here for example.
Aura Bass Shakers are another type of transducer device designed to reproduce inaudible low frequencies, designed to give an extra “punch” to your sound system. The Shaker is usually attached directly to the object to be “shaken”, such as a chair (similar to the Clark Tactile Transducer) in order to realize its effect. Bass Shakers can be used not only by themselves, but in conjunction with a traditional subwoofer setup. They cost around $45, see this retailer for example.
Here is a Tactile Transducer FAQ.