Looking for a cool breeze without the expense of an actual air conditioning unit? Here's a way to use a bucket and some ice to cool down an entire room.
You can build this cooler with a bucket, Styrofoam liner, PVC pipe, ice (in this case, water frozen inside a milk jug), and a small fan. According to the video, it chilled air from 28 C (84 F) to about 7 C, and lasted for about six hours.
The fan can also be run off a small solar panel, which opens up some possibilities for cooling down areas that don't have electricity. Check out the video for a full walkthrough.
Homemade Air Conditioner DIY [YouTube]