Dragdealer JS
http://code.ovidiu.ch/dragdealer
"Dragdealer is a drag-based JavaScript component that embraces endless front-end solutions. Elegantly crafted for JavaScript-aware coders.
2D drag and tap, mouse and touch (mobile tested), 12kB unminified. No dependency."
Ajaxian ยป HTML5 Drag and Drop in deeetail
http://ajaxian.com/archives/html5-drag-and-drop-in-deeetail#comments
Aww, shucks! "Les Orchard isn't just a cool domain name. He is a person. A person who has done a great job detailing HTML 5 drag and drop that you can use today in Firefox 3.5."