sync contacts from iphone to outlook

Follow these directions for a direct sync between your iPhone and your Outlook on your computer:

http://www.copytrans.net/support.php?action=showEntry&data=2258

Or use iTunes and sync your iPhone contacts with Outlook:

http://office.microsoft.com/en-us/outlook-help/synchronize-outlook-and-apple-iph one-or-ipod-touch-contacts-HA010266802.aspx

I have sync'd back and forth that I now have multiple duplicate contact entries. How can I eliminate 'identical' entries.