There are times where it would be nice to be able to select a shape or a board outline (or a group of them) and scale it (or them).
This would be helpful if you have a logo on the silkscreen layer, for example, and need to re-size it (smaller or larger) to fit or utilize an open space on the board.
I would think it would be pretty easy to implement (apart from the mouse or dialog entry of the scale factor, the scaling itself is simple math on coordinates, with no side effects I can think of).
-Brad