Google Maps Adds Locator, But Not For iPhone
My Location approximates your location by using the surrounding cellular towers instead of GPS data, which is often associated with such features.
"It's not GPS, but it comes pretty close (approximately 1000m close, on average)," said Google. "We're still in beta, but we're excited to launch this feature and are constantly working to improve our coverage and accuracy."
To find your location, you simply press the "0" button while in Google Maps. Your approximate location is shown with a blue dot on the map.
User interest in the discussion area for an iPhone version seems high, but the feature is not compatible with the iPhone.