You have several options here - We use Oracle(Weblogic) portal... most of our apps take up a full screen portlet but we get them to play nice inside or outside the protal.
-Deploy using the flex.portal.GenericFlexPortlet
-Deploy as a remote protlet
It can take some time to wire in the app if you need session and portlet to portlet communication.. Also watch our to handle things like hte user hits the Max protlet button in most cases it refreshes the whole page and your app so the user can loose work..
Great information. Do you have any sample(s) that I could use to just get a simple flex to run inside Oracle Portal...along with instructions on how to deploy? All I need is a simple one to get me started. I've dealt with IFrame on Oracle Portal but found our version had to many bugs to effectively use this option, so I'd need more information on your latter two choices ( flex.portal.GenericFlexPortlet, remote portlet).
We user Oracle Workshop for WebLogic here.
1st - I create a new Portal project
2nd - create a new Protal > Choose Java Portlet
Class Name: flex.portal.GenericFlexPortlet is key here
Some minor tweeks...and you can run it under the Workbench - when we deploy we have a parent EAR file we deploy all portal code to.
This basily updates the portal.xml file