On 14/15 September 2006, there will be a workshop about implicit definitions and a priori knowledge in Berlin. Among the speakers are Tim Williamsson, Jason Stanley, Paul Horwich, Crispin Wright, and Dave Chalmers. The website for the conference can be found here.
Thanks to Vanessa Morlock for bringing this event to my attention. Given the workshop format, early registration will be important because of the limit on the number of participants.