It all depends on the type of phone you have, whether you want to connect it directly to the bike, connect through Bluetooth or Bluetooth through a GPS like the Garmin 2820 or Zumo 550.
Whatever way you decide to connect, Kennedy Technoloiges has the device you need. Contact Jon at GoldwingGadgets.com and explain precisely how you wish to connect your phone and he'll get you everything you need to make it "Plug-N-Play" and he can help you with any mounting solution you need as well.
If you already have a Bluetooth capable device like a Zumo, you already have all the hardware you need to connect your phone. The only thing extra that you will need is a cable to tap into the microphone, which you can get from Edsets and other places.