Recent studies have evidenced that the statistical properties of the asteroids' rotation periods are a fundamental source of information on the physics of collisions and on the collisional evolution. Moreover, also the properties of the spin vector may be important to constrain the evolutionary processes. In this context, the Yarkovsky effect (and similar ones, based on the interaction of asteroids with the solar radiation) may play a fundamental role. The analysis of the rotational properties -both periods and spin vectors- may furnish several observational constraints to theoretical models, as well as suggest possible new fields of analysis. These studies support also systematic observational campaigns devoted to the computation of the asteroid poles.