1) open disk utility and run 'repair disk permissions' on your hard drive
2) Try connecting with or without the dock (may be a faulty dock or cable). Also, if you have more than one USB 2.0 port, try a different one. Don't plug into a hub.
3) Launch iTunes first, then plug the iPhone in. It will take a few seconds to recognize/show up.
Make sure you go to www.apple.com and download the NEW version of iTunes that is for iPhone. I had to do that. I had iTunes 7 and found out after 3 tries to activate the iPhone that there is a new update to iTunes I needed to download.
If you do have it, go into your Applications folder and uninstall iTunes (drag it to the trash). Restart the Mac and download/install iTunes again. Not sure why, but I've seen this with a lot of Macs... in some cases it was caused by iTunes 7.3 being installed before OS X 10.4.10.
I purchased my phone Friday, 7/6/07 and I have spent the entire weekend on the phone with Apple Support and AT&T. But still no luck as I tunes still sends error message "Could not complete the ITunes request. The store may be busy.
I was having the same problem and repairing my permissions seems to have fixed it.
To repair permissions:
1) open disk utility: Applications->Utilities->Disk Utility
2) Select your hard drive in the left pane
3) click "repair disk permissions"
Just curious, but why isn't the helpful and solved answers marked anymore? I see at the top that there were 2 helpful and 1 solved answers but nothing to indicate which is which.