how to mark up a photo on the web

Hi semweb and RDFa folks,

Creative Commons is interested in providing guidance on how to mark up
photos online in great detail, using RDFa. We've started, but I thought
we'd check in with folks here to get some more eyes on the problem.

Here's our first take:

http://labs.creativecommons.org/~nathan/image-rdfa/madeline.html

(Nathan, your dog is now famous. Next time, it will be my dog.)

We're trying to mark up:
- license and license attribution
- title
- description
- creator
- tags
- geo
- more?

Are we using the vocabularies correctly? Are there other vocabularies we
should consider for the advanced example?

Thanks!

-Ben

PS: I'll take this opportunity to note what I still find awesome about
RDF and RDFa: even an RDFa syntax expert can and should ask for help on
vocabularies, as those are two very different realms of expertise.