The Ubuntu desktop comes preloaded with a fantastic note-taking application called Tomboy.
While the application can be easily accessed from the desktop Applications menu (under the Accessories sub-menu), it can me cumbersome to have to remember to launch this application each time a desktop session is started.
Fortunately, the tomboy application can be added to the desktop panel in a convenient form. Just right click on an empty area of the panel, and choose Add To Panel. In the resulting window, under the Accessories section, find and double click the Tomboy Notes. Now you should have a little notepad icon in your desktop panel. Click on this icon to access all your notes instantly, or to create new notes.
Using this method will also ensure that the Tomboy application gets added to your panel on every startup, ensuring that you’ll always have quick access to your notes.