We propose Po^2V, a lightweight, network layer position verification scheme for distributed position services in multi-hop wireless networks. Our scheme uses adaptive transmitting power and multi-path polling to improve verification accuracy. We study different attacks against the verification scheme and propose corresponding mitigation techniques. Our analysis shows that while less expensive because no advanced techniques are required in the physical layer,Po^2V achieves a verification accuracy that meets the needs of many applications such as region-based access services, sensor monitoring, or ad hoc geocasting.