Understanding the physics that controls rotation properties of tokamaks is a crucial issue for successful ITER operation. Toroidal plasma flow and flow shear directly impact the control of turbulent transport, edge plasma physics, MHD stability, and the interaction of the MHD modes with external magnetic structures (resistive walls and resonant magnetic perturbations). Additionally, a large variety of phenomena are known to affect the properties of toroidal flows. These include 3-D magnetic fields (both resonant and nonresonant contributions), momentum sources, turbulent fluctuations, and magnetic field transients. [first paragraph from extended abstract]