nestedSortable jQuery plugin

nestedSortable is a jQuery plugin that extends jQuery Sortable UI functionalities to nested lists.

Features:

Designed to work seamlessly with the nested set model (have a look at the toArray method)
Items can be sorted in their own list, moved across the tree, or nested under other items.
Sublists are created and deleted on the fly
All jQuery Sortable options, events and methods are available
It is possible to define elements that will not accept a new nested item/list
It is possible to define a maximum depth for nested items