Time, Energy and Stone Tools aims to refocus archaeological and anthropological interest in technology by demonstrating that theory-building is possible if tool manufacture and use are conceived as products of both environmental factors and social needs. Drawing particularly on optimisation theory in ecology, the eleven contributors examine within a broad spatial and temporal framework a wide range of variable including time, energy, raw materials, risk management and information flow and its place in social relationships. Most concentrate on hunter-gatherer adaptation but key papers examining the impact of agriculture and growing social complexity are also included. A challenging overview by Michael Jochim stresses at once the key role of theory in aiding our understanding of early technology and the embeddedness of tool use in the wider behavioural setting.