This video, via synthrotek, demos their new audio interface for iOS devices.
The iOS audio interface connects to the 3.5 mm jack on your iPod touch, iPad or iPhone. It connects 1/4 inch Mono input and outputs 1/4 inch Stereo.
Synthrotek’s audio interface retails for $25.99. Not that they are offering a couple of variations on this idea at their site with different connectivity.