Sorry but It doesn't work like that man..
Thank you anyway
I just tried it again and it works. Here's the whole story:
1) I'm running JBoss Portal 2.0 on JBoss App Server 4.0.2
2) I got the zipfile from: http://download.jboss.com/jbossportal/samples/helloworld.war.zip
3) I unzipped the zipfile to my JBoss deploy directory so that I have a helloworld.war directory in the deploy directory
4) I restart the app server and go to the main portal page (http://localhost:8080/portal)
5) In the Menu/Page Menu on the left side of the portal there is a helloworld item; clicking on that displays the portlet
Thank you so much Scottt it really worked.. I was just doing a stupid thing..