Have to have my phone.  It will be necessary for many things along the way.  I will be using it to contact not only friends and family while I'm on the road, but also friends whom I will be meeting with and camping with along the way.  Some of the other reasons I'm bringing this...

GPS -  If somehow I manage to take long enough that I'm on the road alone, or, the almost impossible chance that I get lost, I can find my way.
Desktop Connect - I can use this app to connect to my home computer, allowing me to edit my site as well as post to my blog while on the road.
Music -  I will be using it as an iPod as well as Pandora to keep the tunes flowin' as I push the miles away. 

iPhone Accessories I will be bringing...
Waterproof case  -  For the inevitable rainstorms we will ride through, gotta keep that baby dry.
Charging cables  -  Duh...

Instead of sitting in line to plug in to public outlets, I'm hoping that this solar charger will suffice for most of my needs.  It takes in the sun all day, and charges my devices with a usb cable.  Works with my iPhone as well as the GoPro.

A high quality camera in a small package.  This little baby sticks on to my helmet, skateboard, tripod, or any other surface and gives me 1080 HD video.  It comes with a shell-covering that is waterproof, allowing for use in the rain, or even under water.  The case is also made to absorb drops, scrapes, crashes, and anything else you can throw at it.  A multitude of attachments allow me to pivot it at fun angles, and get great POV shots.  It also works great for Time-Lapse photography.  I will be using the video and photos I capture with this to put out a short video about my experience this year at R.A.G.B.R.A.I.

A nicely sized wireless speaker with rechargeable battery.  I can run pandora on my iPhone and stream the sound to this speaker wirelessly to pump music through the ride.  Can't wear headphones or it's impossible to hear other riders, plus, others may slow down to cruise with my tunes!