Drag and drop elements from list into separate blocks
Maybe jQuery UI does what you are looking for. Its composed out of many handy helper functions like making objects draggable, droppable, resizable, sortable etc.
Take a look at sortable with connected lists.
Check this out: http://wil-linssen.com/entry/extending-the-jquery-sortable-with-ajax-mysql/ I'm using this and I'm happy with the solution.
Right here you can find a demo: http://demo.wil-linssen.com/jquery-sortable-ajax/
Enjoy!