Easy question, I hope: If the GPF function is turned on, I've noticed that the GPS icon only appears at the top of the screen when one of the apps, such as Navigator or Maps is turned on. When they're closed, the GPS icon disappears, even though the GPS functionality is still activated. So... should I leave the GPS functionality activated all the time, or does it drain battery power even when no apps are using it, and its icon is not showing at the top of the screen? It's not like turning it on and off is difficult, but if it can be left activated all the time with no little or no negative effect on the battery, I'd rather leave it on. Input please? Thanks.