If you have the TomTom app and an old iphone...

[robopath]

Put it in the glovebox of your car with a cheap charger. You now have a fully functional GPS that can call 911 even without an active sim. I know, not groundbreaking info but may save your butt someday. Had the ah-ha moment the other day looking at a 3G and cracked 3Gs that were collecting dust.
Note: does not work with the original iphone, but all others.

 

[Arnezie]

I think most people sell there old iPhones

 

[nepalisherpa]

Put it in the glovebox of your car with a cheap charger. You now have a fully functional GPS that can call 911 even without an active sim. I know, not groundbreaking info but may save your butt someday. Had the ah-ha moment the other day looking at a 3G and cracked 3Gs that were collecting dust.
Note: does not work with the original iphone, but all others.

I use my old 3G as a GPS device as well.