Remember Homer? 

His family got him a cell phone for safety and to keep track of him.

His daughter calls him every day at noon for lunch.

Homer was picking corn and she calls and calls and calls.  She gets worried so she goes to find Homer.

There he is picking away.  Why didn't you answer when I called she asked?

He grabs for his bibs and no phone.  She calls him right there and there is his ring in the corn wagon.  They dig it out and it still works!