  We introduce a measure Q of bipartite quantum correlations for arbitrary
two-qubit states, expressed as a state-independent function of the density
matrix elements. The amount of quantum correlations can be quantified
experimentally by measuring the expectation value of a small set of observables
on up to four copies of the state, without the need for a full tomography. We
extend the measure to 2 x d systems, providing its explicit form in terms of
observables and applying it to the relevant class of multiqubit states employed
in the deterministic quantum computation with one quantum bit model. The number
of required measurements to determine Q in our scheme does not increase with d.
Our results provide an experimentally friendly framework to estimate
quantitatively the degree of general quantum correlations in composite systems.
