We thank N.B. Simmons, P.D. Gingerich, R.L. Ciochon, L.L. Jacobs, W.J. Sanders, J.I. Bloch, K.M. Muldoon, A.R. Bair, O. Vogel, K. Newman, A. Hebs, and two anonymous reviewers. This research was supported by the National Science Foundation (EAR 9909494 to BFJ) and by the Office of the Vice President for Research, University of Michigan.