How do i delete all my contacts from my iphone 3g at once?
If you are syncing through mobile me and you want to remove all the contacts from the iPhone, here are a couple of steps that might help out. Go to settings > mail, contacts, calendars > mobile me account.
In here, you can turn contact syncing off. If this is on and you turn it off, it will remove all contacts from the iPhone. If this is off and you turn it on, it will remove any contacts from the iPhone and sync what is out on your mobile me account. I think this blog could help you https://macpaw.com/how-to/delete-duplicate-photos-iphone. Here are explained in more detail how each setting can be made on the iPhone. Good luck.