I have to admit one thing that I really hate with Apple is how closely its devices are coupled with iTunes and its as if you really can't do anything without iTunes, adding to the frustration is that you can't sync to multiple iTunes. Imagine you have two systems and would want to be able to sync your iPhone with both the systems and use the same Library, you really can't do that unless you are ready to sacrifice the data. If you wanted the freedom of being able to sync your iPhone with more than one system and continue having same library then below are the steps that you might want to follow.

The below tutorial is based on the assumption that you would be running Windows 7 on your systems but this would not change much if you are running XP.

Step 1: ITunes saves the database and library details under C:\Users\[user name]\Music\iTunes. So in your System 1 go to C:\Users\[user name]\Music\iTunes and select all the files ending with .itdb, itl and .xml and zip them.

Step 2: Chose your own way of transfering the above zipped file to your new system, I e-mailed them. But again its your choice, the end result is that the zip file should be in your neww system.

Step 3: In your new system go to the same place as above (C:\Users\[user name]\Music\iTunes) and copy all the files ending with .itdb, .itl and .xml and move them to a new folder and probably name the folder as "Backup" (This is just to be safe in case we require the original files back).

Step 4: Unzip the files you have got from system 1 to C:\Users\[user name]\Music\iTunes in system 2.

With the above step you are done. When you connect your iPhone and try to sync anything you would not get the message that your existing data in iPhone would be erased. Though it is a 4 step process its actually very simple and should not take more than couple of minutes. Now, if you add any data to either of the libraries you would have to follow the same procedure so that .itdb, itl and .xml files are same in all your systems.

Was the tutorial useful? Were you able to follow the exact steps and get your work done? If you are unhappy or happy let me know @maheshmaestro and also leave a comment here so that I can update the post accordingly.