I'm writing a paper on Global Warming and since I had experience with the add-on last year I decided to use Google Notebook again. Last year it was forced on my class, like you actually had to have an extensive notebook for a grade.
I find it's more useful than simply bookmarking things, and for group projects it has potential since notebooks can be shared.
How do you feel about it? Or how about Google and its plethora of online add-on's in general?