Okay, I've seen this issue come up a lot lately, and I'm curious. I'm curious because I only turn Wifi on when I'm at home, and I only turn my GPS on before I use an app the requires GPS. Turning these radios on and off is simple enough, but it is a little bit of an annoyance, especially GPS when I get that damn dialog every time I open Navigation. Here's what I want to know: Will leaving Wifi and GPS on all the time have any notable effect on my battery life? I don't have any problem with my battery life right now, so a slight effect won't be a huge deal. But I keep reading about Wifi sleeping when the screen is off and GPS being idle unless being called up by an application. I'd like to know the truth. Who has it?