I read just about every sentence of the Ars Technica overview of OSX Tiger and learned a lot, especially the parts where the author drones on about OSX's support for meta-data in the filesystem. I originally thought the ability to add arbitrary meta data to any file or folder was an interesting capability, albeit not particularly useful in day-to-day activities. But then I was just playing around and saw the Spotlight Comments field that's now included at the very top of a file or folder's Info box and I grokked it! Now that there's actually an easy way to both add and to search for meta-data on files and folders, then there's actually a reason to put it in! But not just any meta-data... What's the newest and coolest type of meta-data out there? Yep, tags! And the comments fields is perfect for this!
Obviously nothing has changed in terms of the UI or search functionality, just the way I think about meta data. Before I may have ignored an arbitray field like "comments" even if I could search on it (haven't I been able to do something similar in Windows?). But now that I "get" tagging, I know that this isn't the place for long-winded description of the file or folder, just keywords that I can use to refer to it later. Or if those files are shared on the network, others can use these tags to find the files as well. Fantastic!
The cool thing about this is that it works for the most basic of file types. You can select text files and add meta-data and it doesn't affect the file at all, it's still a simple text file. You can also modify files like photos (which really need meta-data) and also folders as well, allowing multiple-layers of organization ability.
I just thought of a great new OSX Utility. Call it "Diva" (because divas love the spotlight, get it?) which would expand on the "Spotlight Comments as Tags" idea. First you'd be able to select a bunch of files at once and add the same tags to all of them (I just tried it with the Finder and it opened up a bunch of separate Info boxes instead). Secondly, you'd be able to select a file and do auto-magic searches on the web for the file's tags. Third, you could have some sort of file-list pane that looks similar to Google's GMail where you could see files organized by their "tags" instead of folders. Basically, apply any of the stuff we're seeing online now with tagging and apply it to your local or shared file system and you start to see the power of this stuff.