This Wednesday, Google launched its much-anticipated location-tracking service, Latitude, which uses the GPS hardware found in smart phones (such as Google Android phones and BlackBerry and Windows Mobile handsets) to pinpoint your position on a map and share that information with your friends. I've been playing with the software on my BlackBerry for a couple of days, and I've taken the time to explore its features. Here's a guided tour of the Latitude experience.
If you already have a Google Account, you can get started simply by adding Latitude to your iGoogle page on the Web. If you take this approach, you can use your full keyboard and mouse to populate your Friends list. Alternatively, you can browse to google.com/latitude on your smart phone and download the latest version of the Google Mobile app, which has Latitude functionality built in. Once it's on your phone, you can log in and get started.
Before Latitude can do you much good or harm, you'll need to add some friends with whom you'd like to share your location. Gmail users already have a heavily populated contact list to select from, but you also have the option to enter e-mail addresses manually.
Once you've added some friends, their avatars will appear on your map. You'll also be able to see how long ago they last updated their location, either by clicking their avatar in the map view or by looking at their listing in your Friends list. If your friends haven't entered a location for themselves and haven't enabled GPS tracking on their smart phones, you'll just see 'Unknown Location' by their names. In some cases, you'll also see a tiny icon that looks like an eyeball with a slash through it. You might think that this means your friend has chosen to hide his or her location from you, but it actually means the opposite: The friend can't see your location. In this case, you'll need to select that friend and enable the level of location sharing you want to confer.
You have three options for sharing your location: You can have Latitude detect your location to the best of its ability and automatically share it; you can set your location manually by entering an address or city; or you can hide your location entirely. You select the option you want in the oddly named Privacy menu. I think that a better label would be Location Sharing, which describes what actually happens here.
This menu sets your sharing preferences universally for all of your friends. If you like, however, you can change your sharing options for each friend individually. More on this later.
Because you can enter any address you want when you set your location, it's very easy to spoof your position with Latitude. For instance, I'm toying with the idea of telling my friends that I'm in Timbuktu, Mali, because I want them to think I'm a hip jet-setter with a taste for exotic locales. (Sure, it's a stretch, but some of my friends are pretty gullible.)