Somehow I have managed to get quite possibly several hundred duplicate entries in my address book--most likely when synching my phone. I started manually deleting them, but found myself extraordinarily frustrated. I use Plaxo, so I've synched the address book to the online service and I've upgraded my account simply to use the de-duper.

The de-duper merged all those that were identical and then ran me through the remaining contact that were close. The process was painless and quick--it probably saved me several hours of effort. Now to check out the other premium features in Plaxo.