As of October 31, 2008, BlackBerryTracker.com has moved to its new site and design, MoosTrax.com.
If you are an existing BlackBerryTracker user, all you need to do is sign up for a new account at MoosTrax, uninstall the BlackBerryTracker client from your phone, and install the MoosTrax client. You can find out how to download MoosTrax here and register for an account here.