The SMS service has been up and running with the Windows Live Messenger and Yahoo Mail but Google has been pretty slow in this regard. Only recently it has introduced the SMS feature for its valued users and that too for those in the U.S alone.
The service can be activated by simply enabling the SMS chat feature in the Gmail labs settings. The problem here, apart from its service confined to the U.S territory is that users can only send or receive texts from the Gmail site and not from Google Talk. I hope Google speeds this up and expands the service outside the U.S and integrates its chat client as well.
[via Digital Inspiration]