The first thing we did was mark our bean to hold states and have its transactions managed by the server. An example of this is shown here:

@Stateful
@TransactionManagement
public class UserBean {
    ...
}

What happens then? There's no method that deals with adding or removing stuff or do any transaction management. But they are still managed. See the following code:

 Transaction started
 1 added
 Transaction will be commited
 Transaction commited? true

So, you have all the transaction intelligence without writing a single line of transaction stuff. 

It will transact even when the bean releases its resources:

 Transaction started
 User logout. Resources will be released.
 UserBean will be destroyed
 Transaction will be commited
 Transaction commited? true