I am using icloud, but always sync my contacts using itunes. Still have a lot of duplicates. How do I get rid of the duplicates
On your Mac, open the Address Book and goto Card → Look for Duplicates.
You'll be prompted with something like this:
After merging the contacts in the Address Book you should choose to replace the contacts on the iPhone. This option can be found under the iPhone in the iTunes sidebar.
Best to not sync your contacts with iTunes and a cable if you're using Mobile me and/or iCloud. The duplicates are probably because you're looking at what's on your computer combined with what's on iCloud.
Once you choose to sync with iCloud turn off contacts and calendar sync through iTunes. This was true in the "old" Mobile Me days and it's still true with iCloud.
Your problem obviously comes from the fact that you use both iCloud and iTunes to sync your contacts.
There is a bit of a complicated solution but which works. First switch off your iCloud contact sync. Next, go to iTunes and set up a Gmail iPhone contact sync.
If you don't have a Gmail account, create one. Next, sync all of your iPhone contacts with your (new) Gmail account.
Finally, select "Find and merge duplicates" from your Gmail Contacts settings (by clicking on the "More" button).
Make sure you effectuate a sync between your Gmail contacts and your iPhone once again (via iTunes). All of your duplicate contacts are now gone (and whenever needed - merged).
Go to Gmail (from your web browser), and navigate to your Gmail contacts (all of your iPhone contacts should now live in your Gmail too).