  This review describes the physics of spins in quantum dots containing one or
two electrons, from an experimentalist's viewpoint. Various methods for
extracting spin properties from experiment are presented, restricted
exclusively to electrical measurements. Furthermore, experimental techniques
are discussed that allow for: (1) the rotation of an electron spin into a
superposition of up and down, (2) the measurement of the quantum state of an
individual spin and (3) the control of the interaction between two neighbouring
spins by the Heisenberg exchange interaction. Finally, the physics of the
relevant relaxation and dephasing mechanisms is reviewed and experimental
results are compared with theories for spin-orbit and hyperfine interactions.
All these subjects are directly relevant for the fields of quantum information
processing and spintronics with single spins (i.e. single-spintronics).
