This would come in handy. Especially when it comes to user maps with lots of landmarks. While the signs are often interesting, with a purpose, it would be nice if you could hide them until they are needed, then hide them again. As it is now, if they exist, they are shown all the time, and sometimes clutter up the map. I'm mainly thinking about the pre-placed signs made in WorldBuilder here, not the ones you can place yourself in-game, although those should also ideally be included. 
