On the Tutorialzine.com site there's an interesting (though a bit older) tutorial showing you how to combine jQuery, PHP and some CSS+HTML to make a simple sticky note application complete with multiple note support and drag-and-drop abilities.

Today we are making an AJAX-enabled Sticky Note management system. It will give visitors the ability to create notes with a live preview, and move them around on the screen. Every movement is going to be sent to the back-end via AJAX and saved in the database.

They use the fancybox plugin for jQuery to make creating the notes a lot simpler. Included in the tutorial is all of the HTML, CSS, javascript and PHP you'll need to create the application (as well as plenty of description along the way). You can see a demo of it in action here or just download the source and dive right in.