On my 1990 1500..i ran a new lead from the acc fuse box inside the front fairing. Off that lead i installed a usb port that sits inside the left soft pocket. I had the pocket re made to include a velcro pouch that sits on top of the pocket. I stick my phone/mp3 player/ etc...in the velcro pouch...plug it in to the usb sitting in the pocket. Voila...your phone is charging while playing music or talking...and its out of the way to allow you to concentrate on your roads.
As a sidenote...off the same power lead..i also run direct power to a sirius satelite radio and some lighted led switches that turn on/off some purple led lighting. All these things are low consumption because of led power.
Do some testing with power draw and fuse about 1ft from the acc block by installing an inline fuse as your coming off the acc block hookup. I have a 5amp fuse....over 1 year..no issues. You can also fuse the seperate hookups if you like but I would just do one at the acc block.