The real problem for me is that there isn't a good ID3 style tag for images.

I hadn't really thought about this issue, but, yes, it's pretty surprising that no tag-like extension has emerged in something like PNG.

And in an effort to mash even *more* subjects into this thread, I can say I had this very odd thought:

If Ogg has this open-ended "comment" tag structure and should let you include images (say, of cover art), then all we really need is an agreed extension of various comments for photos, then you can add all of your pics to Ogg files (with very short recordings of silence *or* audio comments by the photographer for that matter)

I'm going to go look to see if anybody at Xiph got drunk this weekend and is already doing this!