Water Heaters are the #2 power user. If it's in a cool area, insulate it. Turn if off entirely if it's not needed continuously. Setting it to 120 degrees is usually fine (most are set to 140 by default).

Or as someone else suggested, replace with a tankless system. Leaky faucets also put a ding in the hot water bill.

LCD monitors consume 1/2 to 1/3 the power of an equivalent CRT monitor (the larger your screen, the more you save).

If you're otherwise indifferent, LCD TVs consume less than Plasmas.

If you have an AC, install it on the best-shaded side of the home. Improving ventilation in HOT attics also helps cool the entire house.