Map overlay layers

It would be great to have map overlay layers. One would be able to create any (reasonable) number of layers and turn on or off any number of these layers.

On each layer one could draw then whatever graphics one wanted to draw such boxers arrows, text, lines, etc. However, these draws on the map layers would expand and move with the map it overlays as one scrolls teh map or zooms in and out. So if one drew a box over a given hex that box owuld always be over that hex regardless of map zoom or scrolling about.

It would be great to be able to name the layers as well and even color code them.

This would really be great fro the Gamers TCS games where one has to create numerous map Op sheets, where one could create a map overlay layer for each.

The layers could also be hidden from the other side so that one can hide their battle plans form their opponents.

Has anyone found any kind of feature similar to this? Would like to be able to draw lines on the map, as well as other symbols.