For many biological molecules, force is an important functional and structural parameter. With the rapidly growing knowledge about the relation between structure, function, and force, single-molecule force spectroscopy has become a versatile analytical tool for the structural and functional investigation of single bio-molecules in their native environments. Within the past year, detailed insights into binding potentials of receptor ligand pairs, protein folding pathways, molecular motors, DNA mechanics and the functioning of DNA-binding agents (such as proteins and drugs), as well as the function of molecular motors, have been obtained.