This paper reviews some recent developments on cost-effective flow-based analysis. They include the newly developed Lab-at-Valve (LAV), concepts in using the stopped-flow injection approach, on-line sample pretreatment systems, including bead injection-flow injection and flow injection-ion-chromatography, systems for size-based speciation, and cost-effective reagents. Applications and advantages of such techniques are discussed. (C) 2004 Elsevier B.V. All rights reserved.