It's been available for other mobile platforms for quite a while, but now, the Google Latitude app for iPhone has finally landed on Apple devices.It's a way of tracking your friends and family. Legally of course - Google Latitude certainly isn't intended as a stalker's tool of choice. If you have an iPhone, download the app and you can see where your friends are, with the app even able to run in the background for continual tracking. Your friends don't need an iphone either, with the app on Android, BlackBerry, Symbian, and Windows Mobile smartphones, pretty much everyone can join in, as well as being able to contact you by phone, text message, or email.So how do you stop the wider world tracking you? Easy - you adjust your privacy settings. Latitude is 100% opt-in. You must install the app and add friends (or accept requests) to start sharing your location. You can also turn off background updating, hide your location, limit tracking to city-level or simply sign out. Let's be honest, we all like a bit of privacy some time or other.According to Google, the new app was built 'from the ground up' using iOS 4’s new multitasking capability to support background updating. Which means you’ll need iOS 4 and above on an iPhone 3GS or iPhone 4 to use the app to its fullest. Other devices can still use it, just not with that background work going on. Download it now, it's free of course.