iTunes is one of those application I love and hate at the same time.
I don't sync my iPhone with iTunes very often, but in the last month I have tried several times to sync and the process seemed to be stuck during the backup phase. In order to complete the sync, I had to terminate the backup by clicking on the little x on the right of the top middle status window in iTunes. Not having a full backup left me with an uneasy feeling, I would hate to lose most of the application data I have gathered on my iPhone. After some Binging/Googling, I found that this is a fairly common problem but the fixes seemed over complicated and risky.
Finally yesterday I put some time aside where I could work on the issue. My first approach was to let the sync process go for an hour and periodically monitor its progress. Over the course of the hour I could see the status progress albeit slowly (If you don't look closely, you might believe that iTunes is hung). I decided to let it go another 30 minutes. At the end of an hour and half the backup completed. I decided to sync again, and now the backup is back to normal time (less than 1 minute). Who knows what activity iTunes was performing to complete the backup but patience seems to have triumphed.