If you where using NetBeans 5.5 previously and then switched to the new NetBeans 6.0 Milestone 10 version, don't be surprised if you don't find the “Portlet Application” option while creating a New Project (after installing the portlet plugin from http://portalpack.netbeans.org/)
In NetBeans 6.0 the Portlet Application is part of the “Web Application”. So what you need to do is to create a “Web Application” and in the wizard under the Frameworks panel select “Portlet Support” to create a Portlet Application.





