andersd wrote:. . . .THEN each tag could be linked to a spot on the picture. For example if you have a group picture, the "John Doe" tag could highlight the spot where he is at.. . .
If the desire is to map out x-y pixel co-ordinates of individuals in non-layered photographs, using embedded Adobe XMP (IPTC) tags in (Standard, not JPG2000 or Progressive) jpg files, then I finally understand the question. But I don't know which programs, if any, provide that feature automatically for future genealogical browsing. However you could do that manually today using XMP tagging on XPsp2 or Vista32.
Disclaimer: MediaOne does embed metadata into jpgs using many of the available IPTC fields. In Vista it seems that MediaOne is using the "old" Photoshop 3.0 IPTC Fields for writing and reading. Microsoft PhotoInfo Tool 1.0 writes and reads many of the IPTC metadata fields in both "old" Photoshop 3.0 and "new" Adobe XMP 1.0 format. But Keywords and Captions appear to be the only fields that are readily searchable in Vista Explorer.
If PhotoImpact users need searchable metadata for PhotoImpact UFO, PSD, RAW or other unsupported file types, it may be necessary to create still another 'sidecar' jpg thumbnail file (in the same folder) to include metadata. The hidden UFO.jpg thumbnail files stored in Corel folders do not support metadata at this time.