We present DRR-gossip, an energy-efficient and robust aggregate computation algorithm in wireless sensor networks. We prove that the DRR-gossip algorithm requires O(n) messages and O( n3/2 log1/2 n ) one-hop wireless transmissions to obtain aggregates on a random geometric graph. This reduces the energy consumption by at least a factor of 1 log n over the standard uniform gossip algorithm. Experiments validate the theoretical results and show that DRR-gossip needs much less transmissions than other gossip-based schemes. Categories and Subject Descriptors: C.2.4 [Computer Communication Networks]: Distributed Systems, F.2.2 [Analysis of Algorithms and Problem Complexity]: Nonnumerical Algorithms and Problems General Terms: Algorithms, Design, Performance, Theory