How do I extract Picasa's "Name Tags" for use on Flickr, etc?

I'm quite happy with the feature of Picasa which does facial recognition as a concept, but not in practice. I can't get the data to couple to any other place, and for now it remains in a Walled Garden that is Picasa. I was hoping that I could get it out via EXIF or ITPC tags, but that doesn't seem to be the case.

Does anyone know how I can get this data into a more useful (portable) format?