Whenever I get a new iPhone or iPad, I always set it up wrong to synch w/ MobileMe and get duplicate calendars. This usually tells you how to fix it: http://support.apple.com/kb/HT3677 This time, however, with my new iPhone 4, I could not get rid of a second calendar titled "Birthdays". I keep one calendar on iCal and MobileMe title "Birthdays" and enter birthdays into iCal in that calendar; this second duplicate "Birthdays" calendar doesn't have anything in it, but I couldn't delete it. After two hours with Apple support, and three separate technicians, they decided that the second "Birthdays" calendar is created by Address Book, and that it could not be deleted. So, I've got two calendars of the same name. Inelegant, but no big deal I suppose. If anyone knows how to get rid of the second "Birthdays" created by Address Book, I would be interested to learn the trick. Otherwise, maybe this will save someone a couple of hours on the phone with Apple technical support.