1. Go to Settings at the top right corner of your Gmail page
2. Click the Labs tab in order to go to Gmail Lab
3. Find Location in Signature feature and enable it by selecting the radio button against Enable button
4. On the top of the Labs page, find the Save Changes button and click it to save the changes to the Gmail Labs feature settings you have made. In fact Save Changes would also appear at the bottom center of the Labs settings page.
Again, you need to go to the General Settings tab and find Signature settings
Remember that the above checkbox would appear in the General settings only when you have enabled the Location in Signature Gmail Labs feature. Don’t forget to check the checkbox and save the setting changes by clicking the Save Changes button in General Settings.
5.First time you are to compose the mail, you would get the below pop up window (if Google Gears is installed). As currently I am on Google Chrome browser, I got the below pop-up.
Google Gear uses WiFi access point signals to know your location more accurately for Laptop computers.(reference: gearsblog).
Browsers: If you are on Google Chrome, it is having Gears built in and you need not to install it. But if you are on other browser like Firefox or Internet Explorer or Safari, you need to install it.
And now when you compose new mail or send reply to some mail you have received in the inbox, you would also get your location in the signature as follows:-
The location that Google appends depends on your IP address. If you are using dynamic IP address, maybe there can be a bit variation in the location what is shown in the Signature (sometimes it would show the region or state and sometimes the city, like that!). But if you are travelling a lot for any purpose like conferences or like university presentations or are on some revolving kind of vacation, and if you send a mail to your contacts like business mails or to friends and family, they could know your location and where you were at the time of sending the mail.
Is it not working for you?????
I have found comments from some people that this feature is not working for them. Sometimes clicking on the Compose Mail link twice or sending a test message or two helped them out and the issue got resolved automatically! After all it is a Gmail Lab feature, needs some work out sometimes for someone!
Limitations: Currently, you cannot get the Location in Gmail email Signature when you send emails from mobile based browsers though you can send mails from your mobile phone Gmail interface. May be, this feature would get enabled in near future.