From Arney's link:
...Google wants you to leave your Wi-Fi on, or at least partially on, all the time. Now I know you might immediately scream "MY BATTERY LIFES!!11" but this will probably save battery. Google wants you to leave Wi-Fi on so that apps can get your location, but consider that the other option for location is firing up the GPS chip, which is a battery's worst enemy. ...

Hmmm, WiFi transceiver uses less battery power than a GPS receiver? I'm thinking that transmitting and receiving is a bigger battery drain than just receiving, but maybe the GPS chip is a power hog relative to a low powered WiFi -- dunno. Anybody know the answer?

BTW, another option is to turn location services OFF.