Rated 5 out of 5 stars
Really, a great extension.
Hope it will be soon compatible with firefox 4.0. Something I miss a little is a (customizable) popup menu on selected content when editing (saved) pages with options such as Highlight, Add note, Add inline note, and so on.
A more advanced feature would be the possibility to merge and split scrapbooks in an easy way. It's possible now but not so straightforward, you have to resort to import/export functionalities.
Most of keyboard shortcuts does not work in my firefox, maybe due to conflicts with other extensions.
To use this extension at its full extent it's worth to give a look at the pdf Tutorial.
Thank you for developing it!