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It is shown that the canonical classical $r$-matrix arising from theDrinfel'd double structure underlying the two-fold centrally extended (2+1)Galilean and Newton-Hooke Lie algebras (with either zero or non-zerocosmological constant $\Lambda$, respectively) originates as a well-definednon-relativistic contraction of a specific class of canonical $r$-matricesassociated with the Drinfel'd double structure of the (2+1) (anti)-de SitterLie algebra. The full quantum group structure associated with such (2+1)Galilean and Newton-Hooke Drinfel'd doubles is presented, and the correspondingnoncommutative spacetimes are shown to contain a commuting 'absolute time'coordinate ${\hat x}_0$ together with two noncommutative space coordinates$({\hat x}_1,{\hat x}_2)$, whose commutator is a function of the cosmologicalconstant $\Lambda$ and of the (central) 'quantum time' coordinate ${\hat x}_0$.Thus, the Chern-Simons approach to Galilean (2+1) gravity can be consistentlyunderstood as the appropriate non-relativistic limit of the Lorentzian theory,and their associated quantum group symmetries (which do not fall into thefamily of so-called kappa-deformations) can also be derived from the (anti)-deSitter quantum doubles through a well-defined quantum group contractionprocedure.

From Lorentzian to Galilean (2+1) gravity: Drinfel'd doubles, quantisation and noncommutative spacetimes