  We outline a theory describing the quasi-classical dynamics of composite
fermions in the fractional quantum Hall regime in the potentials of arbitrary
nanostructures. By an appropriate parametrization of time we show that their
trajectories are independent of their mass and dispersion. This allows to study
the dynamics in terms of an effective Hamiltonian although the actual
dispersion is as yet unknown. The applicability of the theory is verified in
the case of antidot arrays where it explains details of magnetoresistance
measurements and thus confirms the existence of these quasiparticles.
