In this hot summer season here in Hawaii, it's tempting to blast the AC, but using your ceiling fans can save you a lot of money on your electricity bill.
Here's an exert from an article by American Home Shield:
"In 24 hours, a standard central air conditioning unit can burn through a great deal of electricity. In the same amount of time a ceiling fan’s electric expense is less than a dime. Running a ceiling fan at medium speed for three hours costs just a penny! In fact, most ceiling fans only use about as much power as a 100W light bulb."