Navizon has a feature called Buddy Tracker where you can create groups and see where everyone is on a map that is in your group.
This is how you would set up your free account where you can earn points to get this app for free:
1) Go here to set up your free account. Remember what your login name and password are.
2) On your handheld, open IE and go to "www.navizon.com" . It opens up the PDA optimized site. Click on the link named Download. This will install it directly to your phone.
3) Log into Navizon on your handheld with the login name and password you you just created.
Otherwise you just follow the same steps above and then upgrade and pay $24 one time fee. I think only the phone that you want track on needs to have the $24 software on it while all the others just need the free version.