I'm working on KDE-Nepomuk for my internship at Mandriva, France
I first focused on allowing the user to link people to files in Dolphin and Konqueror. Akonadi exports its contacts in Nepomuk, so linking pictures to contacts becomes very easy. You can also add the contacts directly into Nepomuk from the tagging window.
Giving it a try
I don't have an svn account (yet), so I host all my code in a git repo on gitorious : http://gitorious.org/projects/nepomuk-peopletag/repos/mainline
Here are step by step instructions to test the code. You'll need Nepomuk installed, plus all the stuf in playground/base/nepoumuk-kde .
1. Checkout the code :
git clone git://gitorious.org/nepomuk-peopletag/mainline.git
2. Compile the lib first :
cd mainline && mkdir build-lib && cd build && cmake -DCMAKE_INSTALL_PREFIX=/your/prefix ../lib && make && make install
3. Tagging regions on pictures : build the kpeopletag component (same procedure as for the lib) and install it. You should now have a "tag people on this picture" action in the right click menu in Dolphin and Konqueror.
3. Dolphin panel integration : That's a bit trickier, as you need to patch dolphin : first build the dolphin component, then use the provided patch dolphin_nepomuk_linkwidget.patch and apply it in the kdebase folder :
patch -p0 < dolphin_nepomuk_linkwidget.patch
Rebuild dolphin, and you should now have a "link to" line field in the panel. 4. What about the ncoengine and plasmoid folders ? They're work in progress, nothing useful yet.