Like so many others using the Google Notebook service, I was totally bummed when they discontinued support a few months ago. I searched and I searched but I could not find a suitable replacement which provided all the various features I've come to know and love in notebook:
1) Grabbing quick excerpts from webpages and letting me add comments.
2) Tracking interesting Quotes (both from webpages and user-entered) and providing it as a feed which I then used at the bottom of this blog.
3) Organizing notes by both hierarchy (notebook/section) and more importantly by tagging.
4) Providing a killer search feature which scours my notebook for all the relevant notes I've left myself which mention that search topic.