SmartGo acts as a client to the Internet Go Server (IGS). At any time of day or night, you can find hundreds of players playing and observing at the server. Simply go to the IGS tab in SmartGo and click to connect.
The IGS home page provides information on how to register your own account. (You can always log in as 'guest' to observe.)
Go to Help - Common Tasks for more help on this topic.