  We review recent results from the X-ray timing of accreting millisecond
pulsars in Low Mass X-ray Binaries. This is the first time a timing analysis is
performed on accreting millisecond pulsars, and for the first time we can
obtain information on the behavior of a very fast pulsar subject to accretion
torques. We find both spin-up and spin-down behaviors, from which, using
available models for the accretion torques, we derive information on the mass
accretion rate and magnetic field of the neutron star in these systems. We also
find that the phase delays behavior as a function of time in these sources is
sometimes quite complex and difficult to interpret, since phase shifts, most
probably driven by variations of the X-ray flux, are sometimes present.
