In this paper, we propose a new heuristic for runtime task mapping of application(s) onto reconfigurable architectures. The heuristic is based on hardware configuration reuse, which tries to avoid the reconfiguration overhead of few selected tasks, by reusing the hardware configurations already available in the reconfigurable hardware. We evaluate our heuristic by performing a mapping of an extended Motion-JPEG application onto a reconfigurable architecture. A large variety of experiments have been conducted on the proposed algorithm for the same reconfigurable architecture model with different FPGA sizes. The obtained result shows up to 45% performance gain by reusing the hardware configurations as suggested by the proposed heuristic, compared to well-known approaches from the state-of-the-art, which do not take into consideration the hardware configuration reuse.