One of my main interests at the moment is in Interpretability Logics. A long term project is to determine the interepretability logic of all reasonable arithmetical theories. Some progres, little however, has been achived in my Masters thesis. You can browse in an html-version of my masters thesis. It is the original non updated version. A corrected version in ps-format will be released soon.
The article on Interpretability which will appear in Erkenntniss from Albert Visser and Joost J. Joosten can be downloaded from http://www.phil.uu.nl/ckipreprints.html.