  We develop a method of finding a Cox ring of a crepant resolution of a
quotient singularity with a torus action and apply it to examples of symplectic
quotient singularities in dimension 4. In addition we obtain a bound on the
degrees of homogeneous generators of the Cox ring in a more general setup,
based on the multigraded Castelnuovo-Mumford regularity and Kawamata-Viehweg
vanishing.
