Tranglos Software: KeyNote: "Keynote is a flexible, multi-featured tabbed notebook, based on Windows standard RichEdit control. It's always accessible with a single keypress, even if you work in another application. Take a look at the screenshots page.
The basic idea in KeyNote is that you can include many separate notes within a single file. This means that you do not need to open several files - for most purposes it is enough to create only one file and hold all your notes inside it. With the addition of the tree-type notes, you now have a three-dimensional notebook: many notes within one file and a multi-level, nested pages within a single note. Optionally, KeyNote can encrypt your data securely using the Blowfish or Idea algorithms. Keynote's interface and behavior are extremely configurable."