The cool new iPhone Horn Stand is an innovative silicone case that slips onto your iPhone to amplify the volume of the built-in speakers by double - no external power required. In addition to the 13db loudness boost, it also doubles as a handy stand that rests horizontally or vertically. It's compatible with iPhone 4 and iPhone 3G/3GS and has a slot for easy access to the dock connector. Great solution.
iPhone Horn Stand