Co-organizer (with L. Anderson, N. Brady and R. Forman) AMS Special Session on Curvature in group theory and combinatorics, Western sectional meeting, Santa Barbara, April 2005
Co-organizer (with A. Nica and V. Reiner) Braid groups, clusters and free probability, American Institute of Mathematics, January 2005
Co-organizer (with N. Brand, J. Kung, and C. Yan) CombinaTexas: a combinatorics conference for the south-central U.S., University of North Texas, March 2002
Co-organizer (with L. Anderson) CombinaTexas: a combinatorics conference for the south-central U.S., Texas A&M University, March 2001
Co-organizer (with L. Anderson) CombinaTexas: a combinatorics conference for the south-central U.S., Texas A&M University, April 2000
Co-organizer (with L. Anderson) AMS Special Session in Combinatorial Topology, Joint Meetings, San Antonio, January 1999