I have iPhone 3GS, upgrading to a 4S or 5; my prob is that I have 30,000 or more contacts and 75% of those are duplicates! Not sure how this occurred; think it was from syncing FB w/contacts multiple times. Apple told me I needed to make up a good list of contacts on my desk top. (Haven't used my desktop for contacts in 3 years!) Then, back it up, wipe out all contacts from phone and transfer over new, desktop list to phone. Please tell me there's a better way. Much too labor intensive.