Google Notebook versus Opera Notes

I have not used [tag]Google Notebook[/tag] yet, because I haven´t been sure what to use it for. I have used Opera notes for a short while, it worked fine, but again, why should I be using it? I can use many tools to keep my notes, with [tag]Opera[/tag] I can keep my notes in my browser, but I am not sure if that´s any easier than using another tool. With [tag]Google[/tag] Notebook, as far as I know, you can share your notes. This way it could be a handy tool for network marketers. We could write notes about how to promote our company, and other members could view the notes. It´s almost like a private homepage, a site only for members. Not sure if it´s any better than using a closed forum (if we think about how to use it as a marketing tool), or if it´s we should use this as a shared application at all. Because I always look at the practical use of any new tool, and Google Notebook looks better than Opera Notes, just because it´s available online and you can share them. ... but why should we use it?