Comment 16 for bug 579443

I think the menu item is great. I think all you need for the user to get back to the map is an ordinary close button at the bottom of the screen. It should also listen to the hardware back button and close on that just to make things consistent.
I'm a bit concerned about needing another service, but I don't think there's another way for it to work when the user is in another Activity so it's the only choice :)