Due to some cosmic craziness, the Address Book on my Mac Book Pro had swelled to over 140,000 contacts! 141,674 to be exact. There were actually even more but I was successful in killing a few off.
I have no idea what caused the duplication bug to occur, but it was way too much for the system to handle and I needed to take a fresh crack at things. There were simply too many to select all and delete or even run the built-in duplicate finder.
~/Library/Application Support/AddressBook in case you are wondering where to find the source data. I trashed the whole folder.