I really see this as just 2 tagging ‘modes’: 1) tagging for yourself, and 2) tagging for others. Of course, 1) and 2) can and often are done as one.

As far as annotation vs. filing goes, I have to admit I don’t quite see the difference in the end. You can call it annotation, filing, categorizing, labeling, etc., but in the end it’s a flat tagging system, unless you fake:hierarchy:through:tags.

Perhaps when you say “filing” you are thinking of a situation where a user has a set of filing spots, a set of categories, and has to fit an item into those categories, and when you say “annotating” you think free-form keywords that we now popularly call tags. If that is so, then I’d argue that using tags to mimic filing into categories counters the whole tagging idea. Categories are too limiting. Think about categories as human races. In a world that is more and more mixed, lots of people no longer fit into any of the traditional race categories. Ideally, people could tag themselves with “racial tags”, and give each of them weight. For a lot of people that would be a much more accurate way of describing who they are.

Funny, I just read the original blog posts and their mentions of keywords vs. tags. When I first created Simpy[1] I used the term “keywords”, but everyone was going nuts about “tags”. In my eyes they were the same thing, or at least very close.

[1] http://www.simpy.com/

Here is also a review on BlinkList that came out today:

http://blendededu.com/2005/07/blinklist-learning-in-blink-of-eye.html

We are still a tiny company (scarry given Yahoo! is now in the space) but are very passionate about it and would love to hear any feedback from new users.

Mike