  We present a model for the efficient simulation of generic bilayer membranes.
Individual lipids are represented by one head- and two tail-beads. By means of
simple pair potentials these robustly self-assemble to a fluid bilayer state
over a wide range of parameters, without the need for an explicit solvent. The
model shows the expected elastic behavior on large length scales, and its
physical properties (eg fluidity or bending stiffness) can be widely tuned via
a single parameter. In particular, bending rigidities in the experimentally
relevant range are obtained, at least within $3-30 k_{\text{B}}T$. The model is
naturally suited to study many physical topics, including self-assembly,
fusion, bilayer melting, lipid mixtures, rafts, and protein-bilayer
interactions.
