My colleague Greg Currie is organizing a workshop on the a priori, to take place here in Nottingham on October 9th. Further details here. Please contact Greg if you would like to attend.
The workshop is timed to coincide with the visit of Nottingham Special Professor Michael Devitt, whose forthcoming volume Putting Metaphysics First includes some work (check out the title of essay 13) attacking the a priori (a popular pastime of late).