Q:

GMapv3 + displaying all markers + polylines at once?

Is there a way to draw all of your markers & polylines on a gmap v3 at once instead of as they occur? When you create a marker like this:
var marker = new google.maps.Marker({
    title: mTitle,
    content: genInfo,
    map: map,
    draggable: false,
    position: pathCoordinates[i],
    icon: iconImg,
    stObj: stObj,
    emtObj: emtObj
});

It appears to draw it on the map you give it at map: map. I'd like to hold off on drawing any markers until I have them all created and ready to go at the same time. The reason is I'm doing map refreshes and for every polyline and related group of markers I draw they are showing up sequentially all over the map. I want them to all appear simultaneously instead. Here's the polyline snipet:
var path = new google.maps.Polyline({
        path: pathCoordinates,
        geodesic: true,
        strokeColor: randcolor,
        strokeOpacity: 10,
        strokeWeight: 3
    });
    path.setMap(gmap);

A:

Similar to your polyline, you don't have to specify the map attribute in the mapOptions when creating a marker. 
Instead you can call marker.setMap(map); later on. 
You'd probably have to add the markers to an array and loop over it, adding them all one at a time.

