Google plays geotag with Gmail

Google Mail users will now be able to let their contacts know where they are when they send an email.

The experimental feature, which was developed as part of Google Labs, detects which city, region and country you're in and adds the information to your email signature.

For example for the person receiving the email, below the person's name, it will say: Sent from: Southwark, London, England.

Writing on the Google Mail blog, Marco Bonechi, the Google software engineer who built the application, explained his thinking behind the feature.

He said: "Some time ago I noticed how all mail systems tell you when an email was written but not where it was sent from. Because I love to travel, the first question in many messages I receive is "where are you?" and by the time I answer I am often somewhere else."

However, Bonechi admits the system won't always be 100 per cent accurate as it uses the user's public IP address to work out their location.

To boost accuracy, Bonechi recommends using Gears - an open source browser plug-in - to support a location module which uses wi-fi access points to provide a more accurate reading.

To get the feature, users needs to activate their signature in Google Mail's settings then enable the "Append your location to the signature" feature under the Labs tab.

Sticking with a location-based theme, Google recently launched the Latitude mobile application, which allows users to locate family members and friends at any given time.