Any advide on transfering iphone contacts to itunes?

[youtuy]

So here's the thing, I accidently spilled water on my iphone 4, although it has been fixed, it still get kind of "unstable", sometimes it just suddenly shut itself down.
Since iphone 5 is coming soon, I think I'll wait till then to get a new one.However, I have a pile of important contacts saved on my watered iphone 4 and I'm so afraid that they'll be gone with the damaged phone right before I could get a new one. But if I can copy these contacts to itunes, then next time I'll be able to transfer them to the new iphone,right? Or just copy to computer? Any difference?
Anyway, I just want the contacts to be backuped, any good idea? I use Dell PC with Win 7 system.I don't mind if I have to pay for a tool but it would be the best if there's a free and easy way.Help me please!!

[mafia-man]

iCloud back up, set your contacts to be backed up and when the wi-fi is on it will get synced.

Forgot to add if you have outlook you can sync contacts between iTunes and outlook

[emsir]

Sync your contacts with Outlook. When you connect your new Iphone, sync your contacts. Thats it

[ballackay]

1. Open iTunes and plug in your iphone
2. Under the  “info” tab you will see a field that “Sync Contacts with :” and give you a choice of which program you want to save your contacts to .By default, it is Windows Address Book.
3. Check the “Sync Contacts With:”box and choose windows Address Book
4. In the lower-right corner click the sync button and all of your contacts will be immediately saved to Windows Address Book

Next time when you want to sync these contacts to your new iphone, you just add them to itunes library, and I belive you know how to do the rest.
Here I find some interesting articles about how to transfer iphone contacts to itunes, maybe it will help you.

[silvia1990]

You can with the help of Outlook on your computer, create a new folder “Group” under contacts ,then Plug in your iphone 4 to sync with Outlook.
In iTunes select this “group”and make sure to select newly created iphone contacts to save in that same “Group” as well.

I suggest you go to apple's support forum for more information about how to transfer iphone contents from iPhone to PC, once you successfully add the items to to your computer you'll be able to add them to your itunes, there's just one simple step's difference.
A few advice here: 
How to transer or backup iPhone contents to PC
http://www.softwarebbs.com/wiki/How_to_transer_or_backup_iPhone_contents_to_PC     (iPad/iPhone/iPod to Computer Transfer)
How to transfer contacts from iPhone to Mac
http://www.softwarebbs.com/wiki/How_to_transfer_contacts_from_iPhone_to_Mac,_copy_iPhone_contacts_on_Mac ( iPhone Contact to Mac Transfer)