In addition to archaeologists who make stone tools for experimental purposes, there is a growing number of flintknappers who make lithic artifacts for fun and for profit. The scale of non-academic knapping is little known to archaeologists, and is connected to a flourishing market for antiquities, fakes, replicas, and modern lithic art. Modern stone tools are being produced in vast numbers, and are inevitably muddling the prehistoric record. Modern knappers exploit some material sources heavily, and their debitage creates new sites and contaminates old quarry areas. Modern knapping is, however, a potential source of archaeological insights, and a bridge between the professional community and the interested public. Modern knapping also is creating a “twentieth-century stone age,” and archaeologists working with lithic artifacts need to be aware of the problems and potentials.