PNotes or Portable Notes is a open source software helps you to organize your tasks and never forget those important things by allowing you to add various sticky notes, in various designs and formats, to your desktop.
PNotes is very small which occupies only 750 KB space on your hard drive.The interface is very simple and intuitive, this program stays in the context menu and you can configure everything by right clicking on the icon.
Another really useful feature of PNotes is it not only act as a visual reminder but can also be set to alert you by playing customizable alarm sounds at a given time or when an appointment is near, at a time you configure.Also you can customise the look with some pretty cool skins and you can also create your own with PNSkinCreator,notes can also be made semi-transparent.
You may also dock notes to any side of screen (all together or each one separately) and get as result a kind of panel.
One more PNotes feature – ability to join notes into groups by your choice. You can create, modify, delete and relocate groups by simple click or drag-and-drop. Changing group for each note performed by dragging it onto appropriate group. PNotes is fully Unicode supported and translated into many languages.
PNotes Portable: http://portableapps.com/apps/office/pnotes_portable