Great little jquery addon to handle parent child relationships and sortable lists.

http://bitsinashortbit.wordpress.com/2007/07/22/nested-sortable-jquery-plugin/

This was written for jquery 1.1.x so if you have any issues with jquery 1.2.x or higher in IE which only allows dragging of objects once. Either downgrade jquery or download idrag_source.js from this post
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