Latitude on iPhone

Finally! Google has made latitude available on the iPhone. Your
location using GPS is sent to Google so your friends can see where you
are. Now I'll have to find out if it updates location in the
background, or if you have to be running latitude to get location
updates.

Unfortunately, it doesn't update location in the background; you have to load the page m.google.com/latitude on your iphone to update your location.