Have you changed your port bindings for the Jetty listener? It is located in jbossweb.sar/META-INF/jboss-service.xml in 3.0.x. It is in jbossweb-jetty.sar/META-INF/jboss-service.xml for 3.2.x.
Note you cannot bind to a port that is already used - if you already have a web server associated with PHP then you cannot use the port that web server uses.
Also, if you are a non-root user in a Unix environment, you will not be able to bind to a port below 1024.
If you have both Jetty / PHP on same server can you set certain domains to work on the default port w/ Jetty and some domains w/ PHP?
If you are using a web server with PHP that supports JK or JK2 then you can direct requests based on domain or on context matches or both to the JBoss-Jetty via AJP13 (the port 8009 listener defined in the Jetty META-INF/jboss-service.xml). You can read more about this both in these forums, at the Apache jakarta.apache.org/Tomcat site and from the Web.