Since the invention of scanning tunnelling microscopy and atomic force microscopy a new class of local probe microscopes has entered the laboratories around the world. Scanning probe microscopy (SPM) uses probing tips to map properties, such as topography, local adhesive forces, elasticity, friction or magnetic properties. In the emerging fields of nanoscience and nanotechnology these types of microscopes help to characterize the nanoworld. In addition, local probes can also be used to modify the surfaces and to perform lithography processes. An important aspect of SPM is the possibility to modify surfaces. The probing tip can be either used to push or pull atoms, molecules or particles across surfaces. These experiments give information about the local bonding and to explore friction and wear mechanisms.