  In this paper we present a new set of asymptotic boundary conditions for
Einstein gravity in 2+1 dimensions with vanishing cosmological constant that
are a generalization of the Barnich-Comp{\`e}re boundary conditions
gr-qc/0610130. These new boundary conditions lead to an asymptotic symmetry
algebra that is generated by a $\mathfrak{bms}_3$ algebra and two affine
$\hat{\mathfrak{u}}(1)$ current algebras. We then apply these boundary
conditions to Topologically Massive Gravity (TMG) and determine how the
presence of the gravitational Chern-Simons term affects the central extensions
of the asymptotic symmetry algebra. We furthermore determine the thermal
entropy of solutions obeying our new boundary conditions for both Einstein
gravity and TMG.
