on getting meta-data from images etc.

I believe (and someone can correct me if I am wrong) that DOM access 
to image/video meta-data is problematic beause of cross-site 
scripting:  e.g. you design a page which you persuade me to load, 
that manages to load an apple-internal image (which you can't see but 
I can) which is titled "iPhone 5G desktop model", and your scripts 
extract that info. from the image and send it back to you....
-- 
David Singer
Apple/QuickTime