ejb3 not appearing in JNDI tree on jboss

I'm new to EJB3, and have limited experience in EJB 2.1.

We have an existing application running on jboss 5.0.1GA using EJB 2.1, and I would like to start using EJB3.

Tutorials like this one and this one imply that all I need to do to get started is to annotate a POJO with @Stateful or @Stateless and jboss will pick it up automatically.

So I've tried annotating a couple of simple POJOs, like this:

@Stateful(description="matt's new test counter")
public class Counter {

private int count = 0;

public int count() {
    return count;
}

public int increment() {
    return ++count;
}

public int reset() {
    return (count = 0);
}

@PostConstruct
public void initialize () {
    // Initialize here objects which will be used
    System.out.println("Counter initialized.");
}


@PreDestroy
public void destroyBean() {
    // Free here resources acquired by the session bean
    System.out.println("Counter destroyed.");
} 

}

There is no sign in the log file or the JNDI of the word 'Counter'. According to the tutorials, in the absence of any other config the container will assign a default JNDI name to my bean.

How do I get my EJB deployed? The old EJBs on our system use application.xml, but I was hoping to do this new one using annotations only.