For my local file system, I’m extremely wary of metadata systems that do not embed the metadata within the file itself, as you then become dependent on that system for the metadata. For example, the first version of Photoshop Album (which is now a subset of Photoshop Elements) had a very nice photo tagging system built into it. But, like a lot of photo tagging software, it stored the metadata entirely within a database rather than embedding the metadata in the files. That’s fine as long as you’re committed to using that particular app for all your photo needs forever; when you decided to switch to a different product, however, too often you end up having to start over. Another common area this causes problems is song rating metadata in iTunes where people invest a lot of time rating songs only to find that a corrupted database or switching to another app renders that metadata useless.

For example, I think it is neat that people can use things like connotea to tag web pages, but imagine if rather than allowing people to tag or add categories to posts on their own weblog, that Wordpress simply said “well, go use connotea or del.icio.us if you really want to tag the content on your blog.” Yuck.

Clearly both MP3 and JPEG show that it is possible to get everyone to generally agree on how to implement data cross-platform into the file format itself. A standard for a simply adding, say, a single text field to all other files would greatly improve our ability to tag and organize files. Its kind of silly that I can tag a picture of an action figure as “Superman” and that will just work pretty much across OSes, but I can’t do the same thing for a text or other file.