[Editor’s note: The following review is part of Macworld’s GemFest 2009 series. Every day until the end of June 2009, the Macworld staff will use the Mac Gems blog to briefly cover a favorite free or low-cost program. Visit the Mac Gems homepage for a list of past Mac Gems.]

If you suffer from prosopagnosia , you literally can’t remember faces. Swedish companies desibelle and GraphicLife have adopted the term as the name for a program that simplifies integrating iPhoto ‘09’s Faces feature with contact information you already have.

iPhoto ‘09 automatically detects faces in your photos and allows you to attach a name to each face. iPhoto can go one step further and store a full name and e-mail address for each person. Chances are the people who show up regularly in your photos are also in your e-mail application. Prosopagnosia aims to spare you the tedious re-entering of data.

Upon launch Prosopagnosia presents icons for Apple’s Address Book, Microsoft Entourage, Google Mail and Mozilla Thunderbird. You can select any or all of these as sources for your iPhoto contact information. Then it’s on to putting names to faces. As you thumb through the faces you’ve defined in iPhoto, Prosopagnosia lists the contacts it deems are likely matches. It’s here where Prosopagnosia can be frustrating. To choose a contact, it must be scrolled into the second position on the list. There’s no checkmark or other positive feedback to affirm which contact you’ve selected. And, there’s no method to just enter info on the fly. After reviewing each contact, iPhoto is updated in a bulk update.

Prosopagnosia is a handy tool for keeping your iPhoto faces up to date. The interface is pretty, but could stand to be more usable. Despite the limitations, Prosopagnosia works.

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[Stuart Gripman is a columnist for Advisor Basics of FileMaker Pro magazine and founder of Crooked Arm Consulting.]