You know, sometimes I need to put the iPhone speakers directly near my ear to hear what’s happening. If that happens to you and it’s a problem, then you should check out the AudioGlove iPhone case, which will function as an acoustic speaker to amplify the sound of the iPhone speakers without needing an extra power source.
The AudioGlove is basically a case for your iPhone, with a bottom part that slides out. The resulting chamber is supposed to amplify the sounds of your iPhone naturally. The amplification is at about 10 decibels more than what you usually get from the iPhone’s built in speaker itself. It also blocks out background noise and wind for the microphone.
You can get the AudioGlove for $24.99 to $34.99 (USD) from their website. It’s available for the iPhone 3G , 3GS, 4, and 4S.