Is there a free location-aware todo list out there? I need something, that: reminds me to buy milk, when I'm near to my favourite shop.

Is there any way to have certain apps automatically turn on GPS when they launch (or at least prompt me if I want to)? For example, if I use voice commands to ask for navigation directions, and GPS is not turned on, I'd like for it to enable GPS instead of guessing from cell towers. Bonus points if it turns it back off when I close the app.