Google Latitude one of my favorite application on my Google Ion Android 2. But Almost all my friends had Apple iPhone and Latitude was not supported on iPhone till now!

Ok my all friends go to Google Latitude

...quote from google blog...

I'm a big fan of the iPhone. I'm also a big fan of the web. So, naturally, I'm excited that today we're finally releasing Google Latitude for iPhone and iPod touch as a web application running in Safari.

Our Latitude web app provides all the core functionality you might expect: you can 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. In fact, if my friends and colleagues back in London haven't yet noticed my absence, they'll see in Latitude that I'm currently vacationing on the beach in Australia. Hi guys, remember me!?

You'll also find basic Search and Directions functionality to help you get around the world. And just like our Google Maps for mobile client apps (and more recently on desktop Google Maps), 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.

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.