  Strongly correlated metals close to the Mott transition display unusual
transport regimes, together with large spectral weight transfers in optics and
photoemission. We briefly review the theoretical understanding of these
effects, based on the dynamical mean-field theory, and emphasize the key role
played by the two energy scales associated with quasiparticle coherence scale
and with the Mott gap. Recent experimental results on two-dimensional organic
compounds and transition metal oxides are considered in this perspective. The
liquid-gas critical behaviour at the Mott critical endpoint is also discussed.
Transport calculations using the numerical renormalization group are presented.
