Editorial: "Single-molecule biochemistry coming of age" (S.H. Leuba, J. Zlatanova).Part I Protein structural dynamics by single-molecule fluorescence polarization (J.N. Forkey, M.E. Quinlan, Y.E. Goldman). Single molecule force spectroscopy in biology using the atomic force microscope (J. Zlatanova, S.M. Lindsay, S.H. Leuba). Mechanical design of proteins studied by single-molecule force spectroscopy and protein engineering (M. Carrion-Vazquez, et al.).The importance of molecular structure and conformation: learning with scanning probe microscopy (B.L. Smith).Twisting and stretching single DNA molecules (T. Strick, J.-F. Allemand, V. Croquette, D. Bensimon).Part II Single molecule measurements of titin elasticity (K. Wang, J.G. Forbes, A.J. Jin). Analysis of single-molecule mechanical recordings: application to actomyosin interactions (A.E. Knight, C. Veigel, C. Chambers, J.E. Molloy). Structural and functional imaging with carbon nanotube AFM probes (J.H. Hafner, C.-L. Cheung, A.T. Woolley, C.M. Lieber).