The iPhone 4's camera shoots pretty decent video if there's plenty of light, but the mono audio quality is kind of lame. This versatile audio interface from Fostex gives your iPhone 4 some real microphones, so you can get decent sound to go with your iPhone video masterpieces.
Unlike the Blue Mikey which works great if all you want to record is audio, the Fostex AR-4i lets you shoot video at the same time. The clever design has three mic inputs, so you can hold the phone in landscape mode if you're shooting video, and turn it vertically when you're just capturing sound.
The biggest catch is the price. At $150 you would think that it must be aimed at the professional user, but what kind of pro shoots video on an iPhone?
In the video you can watch the cute Japanese video blogger Ayano as she puts the AR-4i through its paces.