set order for line items on quote/order

When we create large quotes/orders for customers with many lines, we try to put items in a certain order as they relate to each other. Sometimes when we add another item, the existing items get reordered somehow.

Other times we just want to remove an item and replace it with something else, which does not allow us to control where it shows on the quote/order.

To be able to reposition items via drag and drop (like theme widgets), via sort order or up/down arrows would be a nicety for us and hopefully others as well.