Unplggd and Re-Nest have detailed some very sleek, high tech ways to keep your house cool this summer. These ways can also come with a less than attractive price tag.
An excellent and affordable method can be found by using three things we already have in our house: a fan, large mixing bowl, and ice. While not the sleekest or most efficient, setting a large bowl of ice in front of a fan caused our AC to run roughly half as much in the oppressive heat.
I arranged my fan and bowl of ice in what I found to work most effectively. By tilting the bowl and allowing the breeze from the fan to blow onto the ice cubes copious cool air was blow out into my kitchen and breakfast nook. The metal bowl I used also cooled and the air blowing around the bowl, causing the metal to function as a crude heat sink. Other frozen or chilled items would likely work, I choose ice due to the fact that the cool water left behind continued to cool the room at a reduced rate once the cubes melted.
Give it a try and see if you receive the same results.