Ceiling fans

Ceiling fans don't cool you by circulating the air- they cool by pushing air over you. They do no good "on" if no one is in the room.

Air/tires

Optimally, you should check the air in your car's tires every time you fill up for gas. However, once a month works just as well and is equally as important- low tire pressure results on more strenuous wear-and-tear on the tires causing them to not last as long. Also, improperly-inflated tires lowers your car's MPG.