Google Latitude just landed on iPhone and as with any location-based app, it's always good to know how to turn it off and maintain your privacy when you so choose. This one can be a little trickier than most since it looks like even quitting the app and rebooting doesn't turn off Latitude tracking.
We don't know if this is some bad coding on Google's part, whether Apple's background location API is supposed to be allowed to do this or not, or if this is just the way Latitude is designed to work (scrary if so!) but it just seems to stay on. In order to turn Latitude's tracking off this is what you need to do: