I've recently read about port's ability to cary audio and video IO in addition to data (miniUSB side). What I'm wondering is what's the practical advantage. Any nifty uses of this port on Hero; maybe... different ways to display video or output audio from the Hero?
HTC makes a number of proprietary connectors for this port. For instance, with my old T-mobile Wing (don't recall the HTC model) it came with a mini-USB dongle cable that had 2 more mini-usb connectors. Those 2 connectors could be used to connect up a charger and an htc stereo headset. HTC 2-in-1 Audio Charging USB Cable - Original (OEM) 73H00245-03M
THey also have other ones that appear to have multipe different headset/headphone connectors. ultimately for me it was really most helpful with my old wing which didn't have a headphone port, though i do regularly use that cable and the headset from my old wing to have my phone attached to my computer and the headset simultaneously.