If you want to see how another group, the DataStorm users group does this take a look at
http://map.datastormusers.com/
After the US map loads, scroll down to any user name and click on it.
You get a localized map, with any other datastorm user who is in that area posted as well.
They have recently also added the ability to view everyone on google earth!
http://map.datastormusers.com/kml/108.kml (if you have GE installed)
What's really fun with this group is the locations are dynamic. As they travel around, they run a program which grabs their latitude and longitude from the satellite dish, and registers their location with the map server.
I know the author of this, perhaps I can see if he'd be willing to share a bit?
ps: Here's a google earth link to my home!
http://map.datastormusers.com/kml/00003029.kml
Dale, put me on in Lake Forest CA, just right and down from Kevin's dot!