Extracting XMP tags from pictures

I have successfully extracted IPTC tags from jpegs, but now that I've switched to F-spot I need to extract XMP data. I have found this: http://www.ozhiker.com/electronics/pjmt/library/documentation/ But I have been so far unable to extract the tags. I have an example image here: http://dotancohen.com/xmp_test.jpg This image has the comment "This is a comment" and two tags: "People->Yehuda" and "Place->Sarid". Has anybody invented a wheel to extract these tags and comment as strings? I'd love to see it if so. Thanks in advance. Dotan Cohen http://what-is-what.com