Customize the 'From:' address

New feature has been enabled on some accounts. From now on customizing of From: address field is possible. This way the recepient of your messages will see your alternative email address as sender. To select the address you'd like to use to send the message you can use the drop-down menu in the compose message window.
P.S.
Gmail will send a validation code to your alternative account. It is required to complete the registering process.