Sticky notes are a great way to remember pending tasks or leave a message to someone. But the digital version is even better: the pad never ends and it's more eco-friendly, because it doesn't require paper.
Simple Notes Organizer is a good example of an easy notes application that can be used in your everyday work, just like the original sticky notes. The program sits in your system tray and enables you to create as many notes as you want just by double clicking on its icon. Notes are saved automatically and can also be independently customized –although this option took me a while until I found it: it's actually displayed by a right click on the top left corner of each note.