  Mott insulators with a half-filled band of electrons on the triangular
lattice have been recently studied in a variety of organic compounds. All of
these compounds undergo transitions to metallic/superconducting states under
moderate hydrostatic pressure. We describe the Mott insulator using its
hypothetical proximity to a Z_2 spin liquid of bosonic spinons. This spin
liquid has quantum phase transitions to descendant confining states with Neel
or valence bond solid order, and the insulator can be on either side of one of
these transitions. We present a theory of fermionic charged excitations in
these states, and describe the route to metallic states with Fermi surfaces. We
argue that an excitonic condensate can form near this insulator-metal
transition, due to the formation of charge neutral pairs of charge +e and
charge -e fermions. This condensate breaks the lattice space group symmetry,
and we propose its onset as an explanation of a low temperature anomaly in
kappa-(ET)2Cu2(CN)3. We also describe the separate BCS instability of the
metallic states to the pairing of like-charge fermions and the onset of
superconductivity.
