  We study Cox rings of crepant resolutions of quotient singularities
$\mathbb{C}^3/G$ where $G$ is a finite subgroup of $SL(3,\mathbb{C})$. We use
them to obtain information on the geometric structure of these resolutions,
number of different resolutions and relations between them. In particular, we
treat explicitly several examples where $G$ contains elements of age 2.
