Re: making overlays topmost in z order.

I think you may be misunderstanding what zindex does.

Zindex settings are relative to the container.

It's possible to change the relative positions of things that are
contained inside the <div id="map"> but anything that's outside the map
is either underneath the whole of the map or above the whole of the map.

No matter how high you set the zindex of the markers, they won't come
out of the map div.

The only way that you could possibly place something above the map tiles
but below the markers is to construct it as a child element of the map
div.
--
The Blackpool Community Church Javascript Team
http://www.econym.demon.co.uk/googlemaps/