The solution to the above NullPointer Exception in EJB 3.0 is as follows:
1) Create an Enterprise Application Project in NetBeans 6.0
2) Create new Session Bean, write your session bean code in here.
3) Create a Remote Interface, include the method(s) from the above Session Bean.
4) Create a Application Client in Secure-apple-client node.
5) Write an annotation to call the EJB in the application client.
6) In Java EE 5 we are not required to write a deployment descriptor (ejb-jar.xml). However, if we do have security for the application, we need to specify that in the deployment descriptor.