[noppid]

This is a relativly easy hack. You need to collect the latitude and longitude of each member that wants to participate in a custom field. Then you use a query to get all the participating users GPS info. Then you loop off the java code to create an array of the list. You pop it off and you have a pinned map.

You can get all the google api code you need to do this at http://www.google.com/apis/maps/documentation/ .

one query and you're off.

Of course this is just off the top of my head, I'm using it a bit differently for US members by zipcode from a zipcode db that fetchs gps info for the look ups.