Google released Google Latitude application for the iPhone and iPod touch, available in the Safari browser. The application lets you see the location of your friends on a map and modify your privacy settings so that you control how your location is shared and with whom. To try Google Latitude, type google.com/latitude into your iPhone's browser. And if you miss the experience of launching the app directly from your home screen, you can add a bookmark to the home screen by opening Latitude in Safari and tapping the + icon > Add to Home Screen > Add.
Here is more about Google Latitude for iPhone from its developers:
"You'll also find basic Search and Directions functionality to help you get around the world. And you can press the "blue dot" to be taken to your approximate current location on the map with My Location, thanks to Safari now supporting the W3C Geolocation API.
Google, like Apple, continues to push for improvements in web browser functionality. Now that iPhone 3.0 allows Safari to access location, building the Latitude web app was a natural next step. In the future, we will continue to work closely with Apple to deliver useful applications -- some of which will be native apps on the iPhone, such as Earth and YouTube, and some of which will be web apps, like Gmail and Latitude.
Unfortunately, since there is no mechanism for applications to run in the background on iPhone (which applies to browser-based web apps as well), we're not able to provide continuous background location updates in the same way that we can for Latitude users on Android, Blackberry, Symbian and Windows Mobile. Nevertheless, your location is updated every time you fire up the app and then continuously updated while the app is running in the foreground. And, of course, you can check in on where your friends are, so we think there's plenty of fun to be had with Latitude. Learn more about updating and sharing your location from your iPhone.
The Google Latitude web app currently supports iPhone/iPod Touch OS 3.0 or above. For now, it's available in the US, UK, Canada, Australia, and New Zealand, and we hope to bring it to more countries soon."