GumNotes

I have to confess that my first impression about this application’s name was “this is just another annotation tool”, but I soon realized that there had to be something that made it different from the rest.

"GumNotes" also suggested the idea of “sticky” or “adhesive”, so this gave me a cue to begin my quest for the suspected difference and soon I found it. There is a feature called gum-effect, this means that you can attach a note to a file. So every time you open that file, the attached note will be automatically opened, as well. In addition, you can also specify keywords and the application will keep track of the title of every opened window to show the matching notes. This way you can annotate documents, websites or Outlook.
Except for the gum-effect, you can use this application the same way you use other annotation tools. So, if you are already familiar with this type of applications, you will find no difficulty in using it. The program runs minimized in the System Tray, from where you can perform most operations. The notes can also be used as reminders, setting time and date timers or asking the note to pop up in a given period of time. The application is well-documented either offline or online.
Well, it may be true that there are many note applications around, yet the developers are somehow managing to stamp their personal seal by providing unique features to them. It is up to you, then, to choose the one that best suits your needs.