About person on image: What you are interested in is XMP. Exif is more for technical data and IIM (commonly known as IPTC) is considered obsolete. In XMP you are interested in Iptc4xmpExt and tag PersonInImage this is bag type so you can put in it your own format, preferably XML of course. About maps: I really hope N900 (and its successors) will use real GPS tags and not GSM tricks (which are evil BTW). With them things are really easy. Anyone porting digiKam to ARM?