I currently use the below code to be able to drag an element around inside a div container (this is important, it can't just be dragged around anywhere eon the page). I use mootools to accomplish this, but I am converting everything to use prototype, but I can't figure out how to get this to work with prototype.
window.addEvent('domready', function(){
var container = $('containment');
new Drag.Move('dragger1', {'container': container});
});
Update: I have found that I can use script.aculo.us to do the dragging, but I don't see anyway to confine movement within a defined space or div element.