This works for jetty, but tomcat should be no different.
In the default/deploy directory create a directory named "hello.war".
Inside that create directory "WEB-INF".
Put your hello.jsp inside the hello.war directory.
You should now see your hello.jsp on the url.
Thanks for the suggestion but, there must be a difference in the configuration files when using JBoss with Tomcat, as I get a 404 error - the requested resource (/hello.jsp) is not available.
There is also a note about this procedure under the thread at http://www.jboss.org/modules/bb/index.html?module=bb&op=viewtopic&t=forums/ that doesn't sort it, then you possibly need to change the jboss-service.xml file under %JBOSS_DIST%/server//conf to work with files. However, I've not tried this, so don't know for sure myself.
Alternatively, use build and ant (never to late to learn) and to create a war file that is dropped in the deploy directory. You can find notes about this in the Quick Start guide at http://sourceforge.net/project/showfiles.php?group_id=22866