Google launched Latitude in February as a new Google Maps feature and iGoogle gadget that lets users see the approximate location of friends who opt to share their location.
While it will work on Internet-connected desktops, Latitude works best on Web-enabled smartphones such as the Apple iPhone or Google Android-based mobile devices. As Google's equivalent of Loopt and Brightkite, Latitude lets users communicate with each other on the go and even meet up. Latitude users can add profile photos, send text messages and update their status.
Now Latitude also stores location history, allowing users to see where they've been at any point in time, and provides alerts to tip users off when they're near their fellow Latitude-using friends. Google Mobile Software Engineer Chris Lambert explained Location History, which he promised will not be shared with any other user:
""Enable Google Location History to store, view, and manage your past Latitude locations. You can visualize your history on Google Maps and Earth or play back a recent trip in order. Of course, you can always delete selected history or your entire location history at any time.""
For this feature to fly without fallout from privacy pundits, the key elements are that the information won't be shared and can be deleted by the user.
This is similar to Google's approach to its Web History feature for desktops: Users can delete their Google search history, right down to the specific Web page. Providing such granularity is important in order to keep the privacy hounds off Google's back.
Meanwhile, the beta of Google Location Alerts is straightforward, but it works hand-in-hand with Location History. Drawing on information about past locations, Location Alerts identifies a user's routine locations, such as home or work, and refrains from creating alerts when fellow Latitude users are near. Alerts will only be sent to Latitude users when they're at an unusual place or at a routine place at an unusual time. Lambert explained:
""People also want to know when their friends were nearby, but it's not always convenient to keep checking Latitude to see if a friend has recently shown up near you. After working on this for a while, we realized it wasn't as straightforward as sending a notification every time Latitude friends were near each other. Imagine that you're Latitude friends with your roommate or co-workers. It would get pretty annoying to get a text message every single time you walked in the door at home or pulled into work. To avoid this, we decided to make Location Alerts smarter by requiring that you also enable Location History.""
If Location Alerts works, it will be a boost to location-based services, separating the important alerts from the my-roommate-just-got-home notifications.
Despite the obvious privacy safeguards, the new Latitude features will likely warrant the scrutiny of organizations such as the Electronic Frontier Foundation, which are nervous about location-based services.
The EFF and others are concerned that Latitude, Loopt and Brightkite will enable law enforcement officials to trace suspected perpetrators' history. These services have pledged to require warrants when law enforcement officials request information from their location-based services.
Twitter also expects to roll out geolocation services soon, allowing users to share more relevant and timely tweets.