Google has released the Latitude app for iPhone users. Latitude for iPhone lets you continuously share your location with your friends and family.
The Latitude application will be available through US iTunes store. You’ll need iPhone 3GS or iPhone 4 with iOS 4 or above to use this application. You can also use this application on your iPad.
Since this application supports background updates you can continuously keep your location updated even when the application is not running. If you do not like this feature you can disable it and manually update your location.