I have the RKA tank bag as well, but it currently only holds my GPS,with the plan having been to add a Ham radio for both voice and APRS. For my iPhone, I have a RAM X-Grip, which I use both on the bike and in the truck. On the bike, I picked up a RAM ball that fits under the mirror (I actually have on of these on each side), and use the stock cigarette plug to charge the phone (I have a coil style cable that allows for the movement of the bars).