Fostex has released an interesting bit of gear – the AR-4i audio interface dock for the iPhone 4.

The Fostex AR-4i is a docking interface that connects to the iPhone dock connector, adding stereo microphone inputs with AD converters, to improve on the audio quality of iPhone 4 for video recording, live streaming and recording podcasts.

Here’s an overview of the AR-4i:

http://www.youtube.com/watch?v=5Up8-HCnA_o

Features 

• 3 microphone inputs with plug-in power for vertical or horizontal use.
• Input level control and EQ can be done using the dedicated App.
• 2 x cardioid plug-in microphones come as standard.
• Third-party microphones can be used.
• LED Level Meter for input level monitoring,
• Microphone gain control.
• Headphone jack for input monitoring.
• 2 x AAA batteries for more than 10 hours operation.
• External power can be fed via USB. •Ergonomic design for secure holding.
• Screw hole provided for optional camera gears such as tripod, grip