Brian Conner sent in some impressive shots of a project he is doing with the Irrlicht engine. I made one of the shot of the week, you can see it to the right. I also added the shot to the screenshot section.
If you would like to use the portal rendering method with the Irrlicht Engine, you are now able to do this: Maarten Bosma sent in an Addon to the engine, which does portal rendering. It is not yet finished and a little bit unstable and Maarten is asking for help to bring it to an end. You can find a link to it in the offtopic forum.