Re: Leaving GPS on so it starts up quickly?
Way too many apps seem to want GPS when WiFi accuracy or Where-was-I-last or Pick-from-a-list accuracy are good enough. (And even if I weren't a geek, battery life means I usually have it turned off.)
I'm more likely to use Yelp to ask about a restaurant near some specific city (e.g. home, or where I'm going later today) than near where I am now, but even if I'm not doing that, whatever level of location resolution it gets should be good enough.
I'm more likely to use weather for a specific location (home or work) than "here" - I can see if it's currently raining outside, and don't need 10-meter resolution to tell the temperature when it's actually using readings from the nearby airport anyway.