This may already be known to you but I discovered it quite by accident.
I have my Iphone 3gs connected to my headunit via the Ipod cable and have always used it that way to play podcasts, Music, etc. For Pandora since we don't have Bluetooth streaming available any time I wanted to do the Pandora thing I would connect the Stereo Handphones to the little 1/8th in Head phone jack input on the face of the Headunit. Well the other day I had my Iphone connected to the regular Ipod cable and switched over to the Pandora App and to my disbelief Pandora started playing over the Ipod cable. I did not have to switch cables or anything. I thought it would be nice if I could skip to the next track with my steering wheel controls but when I press Next track it just stops Pandora. So I haven't figured out how to get it to advance to the next track but anyhow, I thought I'd pass this on to anyone that didn't know you can play Pandora via your Ipod Cable and not have to use the AV2 front Input jack.