iPhone developer PolarBearFarm released Face Match [$0.99] to the App Store yesterday. The app promises to bring the feature similar to Apple's iPhoto facial recognition to your iPhone.
Face Match brings face detection and recognition to the iPhone.
Simply take a photo, and Face Match will detect and attempt to recognize people in the photo. Face Match learns every time you name people in a photo, improving recognition accuracy the more you use it.
The app works by uploading images directly to their server where facial recognition is performed. The results are then sent back to your iPhone. As a result, an internet connection is required for use.
App Store Link: Face Match, $0.99