I was suitably elated to have two papers accepted in the last month or so. The first, with Sophia Drossopoulou, James Noble and Matthew Smith, is called Multiple Ownership and has been accepted at OOPSLA. We describe a system of ownership types where objects may have multiple owners. The formal language described is MOJO. The description using simple sets (the 'Venn diagram' decription) is particularly pleasing in its simplicity.
The second paper (Towards an Existential Types Model for Java wityh Wildcards) is written with Sophia and Erik Ernst and describes an OO calculus with traditional-style existential types that we describe as partially modelling Java with Wildcards. It is a nice summary of some of the work we have done towards proving type soundness for Java with Wildcards; which we are still working on, and is looking like it will occupy the bulk of my thesis!
I've been lucky to work some really good people on both papers, and they have been an excellent experience.
I'll post links to copies of the papers once we've made corrections and generally given them a little extra polish.