I could've used one of these yesterday when it was 40°C. The required items don't sound hard to acquire, either: a 20 litre bucket, some ice, a fan, some pipe.
(via LiveLeak)
YouTube Description:
how to make a non-compressor based "5 gallon bucket" air conditioner. simple DIY. items needed: bucket, styrofoam liner, pvc pipe, small fan, and ice. (small solar panel is optional). one frozen gallon jug of water lasted 6 hours. temperature in house was 84F. cooled air was in the mid. 40F range.