It is not difficult to make a Google Maps based map with a pin for each member. They can allow information to be saved on each person entered on the map (any info, such as: name, address, phone, trucks, tools, photos, websites, email address, etc etc).
The "hitch" to using this type of app is that someone has to enter the information into the system, including geo-position coordinates for each person/pin.
Here is a site that allows maps to be built and stored for free (with advertisements).
http://www.mapbuilder.net/
