  We examine spin diffusion in a two-component homogeneous Fermi gas in the
normal phase. Using a variational approach, analytical results are presented
for the spin diffusion coefficient and the related spin relaxation time as a
function of temperature and interaction strength. For low temperatures, strong
correlation effects are included through the Landau parameters which we extract
from Monte Carlo results. We show that the spin diffusion coefficient has a
minimum for a temperature somewhat below the Fermi temperature with a value
that approaches the quantum limit $\sim\hbar/m$ in the unitarity regime where
$m$ is the particle mass. We finally derive a value for the low temperature
shear viscosity in the normal phase from the Landau parameters.
