I\'m using jQuery Sortable and Knockout to maintain an array.
http://jsfiddle.net/daniel_white/KrGY8/3/
Notice when you drag the items, they duplicate or disappe
KO's mapping of items gets a little messed up based on empty text nodes when you are moving things around using jQuery UI sortable.
You can either eliminate the text nodes in your "template" like: http://jsfiddle.net/rniemeyer/KrGY8/5/
Or remove the existing item and put it back to the right spot in two steps (updating the observableArray twice): http://jsfiddle.net/rniemeyer/KrGY8/4/
I also wrote a binding plugin to work with jQuery sortable in Knockout that provides some additional features here: https://github.com/rniemeyer/knockout-sortable