An improved image tagging system that tags images in a mobile handheld communications device, based on the user's contacts list stored therein. The image tagging system compares a face in a given picture (that the user has just taken using the built-in camera) to faces in the user's contacts list images. A matching contact is found in the contacts list. The picture is then tagged with information from the matching contact. The picture is tagged by inserting identification information into a header of the picture.