Algorithmic Challenges for Sensor Networks - Foreword to ALGOSENSORS 2007 -- Topology and Routing in Sensor Networks -- Codes for Sensors: An Algorithmic Perspective -- Efficient Sensor Network Design for Continuous Monitoring of Moving Objects -- Counting Targets with Mobile Sensors in an Unknown Environment -- Asynchronous Training in Wireless Sensor Networks -- Optimal Placement of Ad-Hoc Devices Under a VCG-Style Routing Protocol -- Analysis of the Bounded-Hops Converge-Cast Distributed Protocol in Ad-Hoc Networks -- Correlation, Coding, and Cooperation in Wireless Sensor Networks -- Local Approximation Algorithms for Scheduling Problems in Sensor Networks -- Assigning Sensors to Missions with Demands -- Maximal Breach in Wireless Sensor Networks: Geometric Characterization and Algorithms -- Counting-Sort and Routing in a Single Hop Radio Network -- Intrusion Detection of Sinkhole Attacks in Wireless Sensor Networks.