The Wnt cell-cell signaling pathway plays a critical and evolutionarily conserved role in directing cell fates during embryogenesis. In addition, inappropriate activation of the Wnt signal transduction pathway plays a role in a variety of human cancers. Many recent studies of Wnt signaling have provided mechanistic insight into these dual roles. Here we focus on two areas of rapid advance: (i) the machinery that regulates the stability of the key signal transducer, beta-catenin, and (ii) the effect of Wnt signaling on cellular targets outside the nucleus, the actin and microtubule cytoskeletons.