Google has released it's notebook application. It is not a real application, but actually an extension that runs in Firefox. A version for Internet Explorer is also available. The application is very easy to work with. Standard it will load but not show. A little icon and the text Open Notebook shows in the statusbar of your browser. A click on it will open the application in a small floating window. Just by selecting text in a webpage and clicking either the right mouse menu or the Add note button in Notebook will add the selected text and auto insert the URL to the page you're visiting. You can have several notebooks (see screenshot). A big overview is shown when you login to google.com/notebook.