I keep mine at 78 (thermostat setting, digital) during the day and run a fan to circulate the air in the living room because our older home has a shortage of registers on the main floor.
When Pedro comes home, he usually complains and turns down the thermostat to 74. But it's programmable, and he rarely notices that it goes back up to 76 after dinner and 80 again overnight. The bedrooms are significantly cooler than the living room, so once we're in bed for the night the thermostat setting is basically irrelevant. I don't know what we pay per kwH, but our bill for an 1800 square foot house is usually in the $100 - $150 range, depending on the season (we have gas heat).
Wombles, I suggest turning the thermostat down to 76 and setting up an oscillating fan. The kiddie pool would work for a little while, but you'd have to keep refilling it with cold water (the sun heats up a couple of inches of water pretty quickly), and sunburn is a bitch.