Drag Drop - moving the field during the drag

I want the user to be able to drag a field to a new locoation - having
the field move as they are dragging it.

I can get the cursor to change style during the drag operation
- but I want the field to move as well during the drag.

Has anyone done this before ?  Does anyone have some tips or
code that I can reuse rather than reinvent the wheel

All help appreciated

Scott H