Fix for duplicate iPhone 3.0 Calendar contacts
After updating to iPhone OS 3.0, I noticed several duplicated Calendar events and Contacts. I found this fix, which works like a champ.
Note: choose “Delete from my iPhone” when you delete the MobileMe account. This will wipe out your contacts and calendar until you re-establish the MM link, but it’s the only way to bounce all the dupes on your phone at once.