Ive used PHPNuke and MyPHPNuke and didnt really find either to be very useful. All I simply wanted was a photo gallary forum and article content. I found it easier to try and write my own and port in other software to make it fit into what I was wanting in the end. I would suggest downloading them installing them locally and maybe looking at the code to get an idea how the features work then you can just build from there on your own. But like others have mentioned they are not coded the best in the world. I also like phpBB I use it for one of my sites as well and am working on customizing it into the rest of the site.