  We discuss collective spin wave excitations in triplet superconductors with
an easy axis anisotropy for the order parameter. Using a microscopic model for
interacting electrons we estimate the frequency of such excitations in
Bechgaard salts and ruthenate superconductors to be one and twenty GHz
respectively. We introduce an effective bosonic model to describe spin-wave
excitations and calculate their contribution to the nuclear spin lattice
relaxation rate. We find that in the experimentally relevant regime of
temperatures, this mechanism leads to the power law scaling of 1/T_1 with
temperature. For two and three dimensional systems the scaling exponents are
three and five respectively. We discuss experimental manifestations of the spin
wave mechanism of the nuclear spin lattice relaxation.
