The Bone Collection Portable Amplifier for iPhone looks like those amplifier horns on antique record players. It’s made of silicone, and it adds 13 dB of sound pressure to the iPhone’s speaker output without using any power. In addition to amplifying sound, it also acts as a stand to prop the iPhone in a horizontal or vertical position. The Bone Collection Portable Amplifier works with the original iPhone, iPhone 3G/3GS, and iPhone 4. It is available in green, black, white, or light brown from Amazon for $24.95.