The paper reports data obtained on a simple micropump, suitable for electrolytes, based on the periodic growth and collapse of a single vapor bubble in a microchannel. With a channel diameter of the order of 100 µm, pumping rates of several tens of µl/min and pressure differences of several kPa are readily achieved by the system. The pump is notable for its effectiveness, simplicity, absence of mechanical moving parts, robustness and low cost. In the absence of a complete theory for the device, the data are interpreted and rationalized on the basis of simple physical arguments. It is also shown how the pump can induce strong mixing in two channels coming together at a Y-junction.