This is a nice example of how to control Google Maps.
With this Labview VI you are able to:
1-Control the center Point of the Map with the desired coordinates.
2-Control the Size, Zoom and the Format of the Map (terrain, hybrid, etc).
3- You are able to put multiple balloons, and change color, size,, etc.
4-You are able to draw paths between the center point and the balloons.
You can attach multiple GPS and display the position of each with a balloon, please modify it to your needs.
The bad: Is a little bit slow, depending on your internet connection.