One of my clients wanted a list box like that. We actually had a sort-of-working model using arrays to track what was highlighted before and after each move. But it was too slow with more than 50 or so entries, so they decided not to use it. Problem was that every mouse click meant we had to scan the entire list to update 2 arrays because of the way multiselect works (shift-click, ctrl-click, etc.).
>I would like a list box that can highlight and move blocks of items together instead of one by one. Any suggestions?