A new experimental Gmail Labs feature Location in Signature, now detects your location and appends the city region and country names to your signature. To turn on, go to Labs tab under Settings, then go to your signature preferences and check the box next to “Append your location to the signature.” It'll use your public IP address to determine your location, so it may not always be that accurate. For more accurate location detection, make sure your browser has a version of Gears that supports the location module. That way, Gears can make use of wi-fi access point signals to recognize that you're actually in London, explain Marco Bonechi