The MicConnect from Griffin Technology is a small interface box that connects professional-level microphones with an iPad, iPhone or iPod touch.
The MicConnect offers as an input connector an XLR. An extra nice touch is that the MicConnect offers 48V phantom power so condenser mics can be used. Dynamic microphones can also be used since the phantom power is switchable. This allows for improved audio input for recording and editing software used on an iDevice.
The connection to the iDevice is through the 1/8-inch headphone/headset jack. Price: $39.99