This happens with almost all the iphone users that they need to wait for a long time each time they sync their iphone to iTunes, as each time while syncing iTunes makes a backup of all the data on your iphone. It becomes a major annoyance some times when need to get away soon, in case you have added some songs to your iPhone or iPod touch and you are waiting for sync to be complete.
iPhone/iPod Backup Switch allows you to disable and enable the iPhone backup process in iTunes. This application is a freeware and works with all the versions of windows including windows 7 and it requires iTunes 8 or 9 to be preinstalled. There is a backup and restore feature that will keep a backup of any files that are modified.
This little utlity can really save a lot of time of yours many time while syncing your apple device with iTunes. You can simply turn off iphone data backup while syncing when you are in a hurry. You can also refer this manual procedure to this on mac os