CES, Mophie showed off a prototype of its Pulse game grip for the 4th-generation iPod touch, which features battery-powered front-facing stereo speakers and haptic feedback by Reflex Technology. We spent some time using the Pulse and came away rather impressed. Game audio, music, and even the keyboard tick sound get translated into convincing pulses and vibrations. The iPod touch interfaces with the Pulse via the 3.5mm headphone jack, and a switch on the bottom left edge turns the haptic feedback on and off. As a bonus, the Pulse also offers full case protection. No word yet on availability or pricing, but you can check out the prototype in the gallery below.