As mentioned previously only cooling the area surrounding you saves energy because you aren't cooling your whole house. One product that touts this is the Bed fan for cooling your bed area while you sleep. I'm not sure how well it works but it's nice to see that products are being touted for saving energy by localized cooling.
Bedfan Bed Fan sleep cooler save energy: "We are doing this for several reasons. One is to make it simpler for people to make their purchase without the full payment up front. Once you have fully tuned the Bedfan® to the most efficient setting you should be able to recover your investment in a very short period of time, Some people are able to recover their cost within a month. See our savings table for further explanation."