Fleck Beta Open to the Public
Nope, that's not a typo for Flock. There is a web service called Fleck that has been building a web annotation tool for about a year. Essentially, Fleck adds another layer to the web thus allowing you to add information instead of just consume it. Ideally you would use Fleck to note things as you saw them. For example, a web designer might leave a note for himself/herself on Sitethrive saying "remember to ask them how they organize their CSS."
Fleck web annotations aren't just restricted to personal use. You can share these notes with others or even blog them with the help of a browser bookmarklet or Firefox extension. Fleck currently has problems with Internet Explorer so the Fleck team recommends using Firefox for the time being. However, the best thing about Fleck is that you don't even need to create an account to use it.
The Amsterdam-based Fleck team plans on bundling more features to help annotate on the web (things like adding photos to notes) before they hit a final release. Interested users may even opt to check out their pro service with premium features for around 3 per month.