I noticed the yesterday that I had a HUGE number of duplicate contacts on my phone. I also noticed that I had all sorts of contacts that just did not belong. I sync my iPhone from our company Exchange Server from Outlook so of course I blamed my updated iPhone.

Then I took a closer look at the Contact Groups that were being synchronized with my phone. I noticed a new group Suggested Contacts.

Then I looked in Outlook 2010 and found that there is a new contact list that appears to offer up discovered contacts. The only problem is that they are synchronized to my phone, all 567 of them.

Mystery solved.