  Recent achievements in semiconductor spintronics are discussed. Special
attention is paid to spin-orbit interaction, coupling of electron spins to
external electric fields, and spin transport in media with spin-orbit coupling,
including the mechanisms of spin-Hall effect. Importance of spin-transport
parameters at spin-precession wave vector $k_{\rm so}$ is emphasized, and
existence of an universal relation between spin currents and spin accumulation
at the spatial scale of $\ell_{\rm so}\approx k_{\rm so}^{-1}$ is conjectured.
