At the moment I am thinking about rigidity theory, in the sense of bar and joint frameworks various other related structures. I am also thinking about a problem related to automorphisms of directed graphs.
I have also recently been interested in linear spaces of nilpotent matrices and in unitary groups over finite local rings.
A long time ago, I wrote my thesis on homotopy theory, and I am still interested in topology.
Here are the slides for a talk that I gave at a workshop on Geometric and Topological Graph Theory that was held at Bristol University in April 2013. Here are the slides of an introductory talk on rigidity theory that I gave at NUI Galway just before the Bristol conference.
I gave a talk on spaces of nilpotent matrices at the DeBrun workshop on Linear Algebra, Matrix Theory and Applications in December 2012 - the slides are here.