Remarkable progress has been achieved in the last several years in
quantum manipulation of Josephson junction circuits and of spins
in quantum dots. These artificial two-level systems can serve as
building blocks of quantum computers, i.e., qubits. Josephson
qubits have been successfully coupled to microwave or
nano-mechanical resonators and various phenomena, usually
considered in quantum optics under the title "Interaction of light
and matter", have been observed. The qubits play the role of atoms
while the resonators substitute the light. In my talk I will
review these achievements and, then, concentrate on our recent
analysis of lasing and cooling in a system consisting of a
Josephson qubit coupled to a slow oscillator. I will also discuss
the role of dissipation in solid state qubits, especially, that of
1/f noise.