Mobile phones or smart phones equipped with different communication technologies and sensors have become pervasive application development platform for opportunistic and human-centric sensing. Optimisation of battery energy consumption and opportunistic sensing coverage are important issues under mobile phone sensing. This paper proposes a simple sampling algorithm based on human-walk velocity for mobile phone sensing. We analyse the impact of human-walk velocity on battery energy consumption and spatial coverage for mobile phone sensing by considering general regular sampling of sensors and proposed sampling method. When Levy walk mobility parameter α = 1, the proposed sampling algorithm shows better performance in terms of both spatial coverage and reduction of battery energy consumption for mobile phone sensing activity. © 2014 IEEE.