This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
It is possible as long as the war files are rolled up inside one ear.
If you are using Rational Application Developer, you can go to the enterprise application and open the /META-INF/application.xml file in the Deployment Descriptor Editor. From there, go to the Overview tab and check the "Shared session context" box.
This generated a file called ibm-application-ext.xmi in the META-INF folder under RAD. If you are not using RAD, please let me know and I will post the contents of this file for you.