For those of you not aware, Google Notebook is a little online notebook for keeping track of "stuff" while you're online. What's kind of neat about it, however, is the way that you use it. In addition to the main interface, you can get a browser plugin that will open a mini-interface on whatever page you're currently viewing and allow you to do the core tasks. It'll also automatically reference the page your on as part of you note, which makes for a handly little way to do "super bookmarks".
Like everything else Google, it's attached to your Google account, so you can access it from any computer that you're signed into Google on. That includes the plugin, which is a nice touch. A lot of plugins I've seen require you to configure the account they'll access as part of the plugin config, rather than using a standard cookie-based HTTP session.
As one last little tidbit, you can make one or more of your notebooks (you can have an arbitrary number) public if you so desire, so anyone can view them.
Granted, it's not a mind blowing app, but it is something that's useful. As is their style, they've boiled the application down to it's essence, and implemented just that core in a well thought out and easy to use manner.
I totally agree with you. It is very useful and has always come in handy to store little info i come across the web as I browse.