Worked For Me!!
Quoted from apple boards:THis worked for me just now (Friday, 10:22 EST)
I just got off of the phone with iPhone tech support. (had to use my landline!)
After a 20 minute wait, I got to talk to Ashley. She said there are 1100 people on hold and everyone she talked to so far is having the same "accessing iTunes" problem.
She said DO NOT disconnect your phone. Intead, when you get the message saying it timed out, click ok. Then click on any other heading, Music for example, in your itunes. Then go back and click on your iPhone icon.
Keep doing this repeatedly to keep your place in line.
I did this for the past 10 minutes STRAIGHT through and I am now done!!! Honest to god! I dont know how to do screen shots or whatever, but I'm done.