Coarse-grained models: getting more with less

There has recently been a proliferation of simplified, coarse-grained models to study aspects of biomolecular dynamics, binding, assembly and folding. Despite differences in construction these various coarse-grained models share a common underlying desire to identify the minimal set of variables required to realistically describe the essence of these molecules. Recent results emphasizing common and distinctive features are highlighted. For someone not involved in developing such models it is a daunting task to decide which, if any, coarse-grained model would be appropriate for a given system. Although this decision ultimately depends upon what kinds of questions one is probing, suggestions about reaching a conclusion are provided.