A service called Google Latitude can be used to track anyone on Google Maps. Google Latitude works with global positioning system devices in mobile phones or can be set manually by a Latitude user. You will need permission from the Google Latitude user to be able to track him or her on the service; once you have been invited to join the group of people who can track that person on Latitude, logging into Latitude will provide you with the person's live location.
Go to the Google Latitude web site and create an account. If you already have an account with any Google services (such as Gmail or Google Voice), you can add Latitude to your existing account.
Access Latitude in one of two ways. To view it in a web browser, click on the link on the Latitude page to add it to your iGoogle page; it will then be accessible at http://www.igoogle.com. To use Latitude on your cell phone, open your phone's web browser and go to http://google.com/latitude. The site will automatically determine if your phone is compatible--and if so, will provide a line to the mobile software.
Ask your friend to sign up for Google Latitude and to add you to the list of friends who are able to track him or her using the service. You can also add the person to your friends list in Latitude, which will enable him or her to track your location as well.
Open Google Latitude in your web browser or your cell phone to track the location of your friends on the list in real time. Their current locations will be superimposed on Google maps. You can scroll around the map or use the arrow keys to browse through all of your friends' locations.
If you wish to temporarily stop tracking your location in Google Latitude, set your account to manual updating. Your location will then be updated only when you log into the site to set it yourself.