While I agree I don't want anyone from home to contact me, I do like everyone in our group to have their phones on, that way if one gets separated or goes off on his/her own, they can be reached easily.
We were just in San Francisco, and DD (15) could go off on her own (slightly) and we could be in contact with her.
DW is a prolific shopper, If I could go my way as she goes hers, the phones are a good way to stay in touch.
We use spring, So if I hear right they will work in key west, GC, but have heard not in CC, and no word on cozumel, right?
Jim