Google is 'finally' announcing Latitude for the iPhone, but can't put it on the Google Maps application at the request of Apple.
The reason behind the 'request' is Apple doesn't want confusion between a Google Maps App and the native one that comes installed on the iPhone.
However, it's also likely that the iPhone's inability to run applications in the background was a stumbling block too, something Google alluded to in its blog:
"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 Window Mobile.
Worked closely with Apple
"We worked closely with Apple to bring Latitude to the iPhone in a way Apple thought would be best for iPhone users.
"After we developed a Latitude application for the iPhone, Apple requested we release Latitude as a web application in order to avoid confusion with Maps on the iPhone, which uses Google to serve maps tiles."
However, Google did confirm the presence of new and shiny applications for the iPhone from the search giant, such as YouTube and Google Earth, in the future, so it's not all iPhone doom and gloom.
Users wishing to get all Latitude-like just need to head over to the site on their Safari Mobile browser and can get all the normal info too, like local search and My Location, which recently debuted for the iPhone web browser.