ZapNotes.  Use this always-ready notepad, which automatically saves its
content.  One of the differences between Notepad/Wordpad and Zapnotes is
that you don't have to use the Control+S to save your file.  The file is
automatically saved every minute unless you change that default.  You 
write your notes,  close the file, and when you open the file again, the
notes are in the file for you to work with.  If you want to create a new
file, the old file will be erased, but not before the program asks you if
you want to save the notes you've written.

The files are saved in the c:\program files\zapnotes folder.  You can export
your notes to a text file and import other  text files.  You can insert the
date and time into your notes with a keyboard command.

There is a system tray icon, though you can bring it up with a
hot key so you can pull the program in from anywhere.