Nanotribology is a relatively young research field which still bears many undiscovered and unexplained phenomena. Despite the fact that friction of nano-meter sized mechanical contacts behaves in general quite differently from macroscopic friction, the motivation for us to have an activity in nano-tribology is that part of the discoveries may well be transferred to the more relevant mesoscopic length scales, and that nano-tribology gives access to mechanical and electronic properties at the nanometer lengthscale. For instance the kinetics of water capillary condensation from background humidity was found to be at the origin of the variation of friction force with sliding speed, and friction forces could be related to an effective atomic interaction potential. We are currently investigating friction and deformation of surface adsorbed objects carbon nanotubes in order to derive estimates of their mechanical properties, such as radial Young moduli and shear strength.