Prosopagnosia transfers contact information from your address book and into your iPhoto Faces. It currently supports Apple Address Book, Gmail, Mozilla Thunderbird and Microsoft Entourage.
Having your contact information stored in iPhoto as well enables you to upload your images to Facebook without manually having to tag your iPhoto Faces with full name and email address. Just use first name or nickname when tagging your contacts, and Prosopagnosia will automatically find matching contacts in your address book.
Starting with version 8.0.2 rudimentary address book integration is built into iPhoto, which allows you tag Faces using the contacts found in your address book. Prosopagnosia, however, takes this one step further, allowing you to transfer contacts from other address sources than Apple Address Book as well as transferring contact information into already existing Faces.
Prosopagnosia can also set contact images in Address Book, Gmail and Entourage using the face key images from your iPhoto Library. When setting contact images in the address book this will in turn sync the contact images to your iPhone or iPod Touch.