CritLink was even more ahead of its time than Third Voice. :-)

This reminded me of a plug-in from 1999, Third Voice.
http://www.wired.com/news/business/0,1367,42803,00.html
I never used it, I had to google to even find its name, but there sure which much hue and cry over it. I'm thinking it was ahead of its time. A Third Voice today would probably be tied into an existing IM system so you would see notes written just by your Buddies. Of course if you want the notes to be present even when buddies are offline, you still have the problem of having to store all those notes. Maybe MSN will add something like this to extend their "shared browsing" feature.

I only vaguely recall hearing of this project, the Annotation Engine. It uses a proxy rather than a plug-in to do its work which allows both links and notes.
http://cyber.law.harvard.edu/projects/annotate.html

Blosxom is going to crush MT and Blogger.

Ok, maybe not, but it is so clean and simple and free, free, free.

Annotation is one of those things that I can't quite figure why it never caught on. Does anyone remember the annotation feature in NSCA Mosaic? You could make notes about a page at a particular point, and those notes would be saved locally. This is just another step, allowing anyone to dynamically add new information without giving them the ability to change what it is you're saying (wikis do that, but you have the potential to loose your voice, as it were).

Now, why can't share your annotations/comments with everyone else? Why shouldn't you, more to the point?

I actually envision a browser plugin that pastes Crow, Joel and Tom Servo at the bottom of my brower window, and when it finds an annotation someone wrote for something on the page, they speak up. But that's a ways off.

That might be a good standard functionality to suggest via the Social Software Alliance (http://www.socialtext.net/ssa/).