According to a post on theiphoneblog, Google Blogs has now announced that iPhone 3.0 now features the rumoured geo-location based services in Mobile Safari and is being put to use in “My Location” searches by Google on the iPhone.
When you visit Google.com from the Safari on the iPhone 3.0 the user can choose to turn on My Location simply but tapping the link in the web page. Tap the “update” link and your location will be updated and displayed on the homepage.
Google has said the service is an opt in and can be switched off through the preferences link on the homepage, and currently works in English UK and US only with other languages being added soon.