"Backpack is a simple web-based service that allows you to make pages with to-do lists, notes, files, and images. Backpack also features a Calendar and Reminders that can be sent via email or to your cell phone at predefined times."
Backpack is another application from the Collaborative Web pagecast that I hadn't seen/used. Since I'm retired I really don't need to make long or involved to do lists, so I didn't sign up to try the site out, however, the examples provided show a wide range of uses. Here is pagini's blog about how to use Backpack for taking notes.