If you have a lot of applications in your iphone, you know how long it can take to sync your iphone with itunes. It needs to first backup the iphone and then sync. It is more aggravating when you just want to put sync that one album or podcast for your train ride to work! It turns out, you can easily disable that feature. Of course its not an option you can disable or enable in itunes. I wish that were the case. People have written programs to do that. All it does is update the %appdata%\Apple Computer\iTunes\iTunesPrefs.xml file with the instructions on not to backup. If you want to enable it again, you have to remove those instructions. One third party app which does that is call Backoff. It can toggle this setting on and off.

Just in case you want to do this yourself, here are details on how to do it -

1. Locate iTunesPrefs.xml by going to Start->Run and typing %appdata%\Apple Computer\iTunes and hit OK.
2. Backup iTunesPrefs.xml
3. Open iTunesPrefs.xml and search for User Preferences
4. Under the next add the following:
5. Save your changes and restart iTunes.  Auto-backup is now disabled.