Tomboy is convenient note-taking program. Anytime you need to jot down a note, you can press ALT-F12 to open the Tomboy menu.

From the main menu you can create new notes, select an existing note or search your notes and notebooks.

You can easily refer to webpages or other notes – Tomboy automatically creates links to both URL's and other notes.

You can quickly search for notes, and group your notes together into notebooks: