Daniel I. Goldman is an assistant professor in the School of Physics@the Georgia Institute of Technology. He received his Ph.D. in physics from the University of Texas@Austin in the Center for Nonlinear Dynamics, studying fluidization of granular media. He followed with postdoctoral training@the University of California@Berkeley in the Department of Integrative Biology, studying biomechanics of climbing and running cockroaches. He has been awarded a Burroughs Wellcome Fund Career Award@the Scientific Interface and a Sigma Xi Young Faculty Award. Address: School of Physics, 837 State Street NW, Georgia Institute of Technology, Atlanta, GA 30332-0430. E-mail: daniel.goldman@physics.gatech.edu