Single-rail handshake circuits are introduced as a cost effective implementation of asynchronous circuits. Compared to double-rail implementations, the circuits are smaller, faster, and more energy-efficient. Furthermore, in contrast to common belief, all four phases of the four-phase handshake protocol can be productive. An important selling point for single-rail circuits is that they can be implemented in any (generic) standard-cell library. This facilitates technology migration and makes asynchronous circuits a potential technology of choice for low-power applications.