Continued use of GPS running in the background can dramatically decrease battery life.
Cerca is a real-time, location-centric, social networking app for you and your best friends. You can use Cerca to see which of your friends are available to hang out at any moment, and what part of town they are at--"coarse grain" locations, like on campus or downtown. If you see a friend near you and want to hang out, call or text them right from the app.
Bring you friends together with Cerca, and forget about sending "where r u" texts ever again!