Here are some of the conferences which I helped organize:
CONCUR 2005: Concurrency Theory, 16th International Conference, San Francisco, California, 23-26 August, 2005. I was the general chair and, with Martin Abadi, program chair.
GDV 2004: Games in Design and Verification. Workshop co-located with CAV 2004 Boston, Massachusetts, USA July 18, 2004 (I was the program chair).
PAPM-PROBMIV 2001: Joint PAPM-PROBMIV 2001 Workshop, Rheinisch-Westfälische Technische Hochschule (RWTH), Aachen, Germany, September 12-14, 2001. Stephen Gilmore and I were the program committee chairs. The web page is not at its original location: the original location was at UC Berkeley, where I was a postdoc at the time.