We explore a new method for reducing power consumption/dissipation for FPGAs which is complementary to existing FPGA technology-mapping power-reduction techniques (e.g., [I@). Our approach is to reorder the input signals to the k-input look-up tables (k-LUTs) SO that switching activity (and hence power dissipation) inside the look-up tables is minimized. We present algoTithms which compute switching activity inside k-LUTs in optimal time. Our experimental results indicate that k-LUT input ordering is very effective at Teducing power dissipation within k-LUTs, providing savings of 26 % on average [2] (savings us. maximum are even greater).