I've enjoyed the discussion so far. I have had an AT&T card for so long that I don't physically have the card anymore - just the number and PIN in my head. It works fine in the USA and at least in some other parts of the world (all the places I've been so far), although there was a time when certain rural western US local telecos completely blocked access to everyone but their own long distance - but not so any longer. As far as I know, 1-800-CALL-ATT works everywhere in the USA now. I used to have the international access number memorized, but I haven't used it for a long time - reminds me that I should put that # in my PDA.
But for our children, pre-paid calling cards are better, so that's what they have. And speaking of kids...
The reason I carry a cell phone with me at all times is so that OTHERS may contact me. Shortly after cell phones got smaller than the old "brick" Motorola type, my wife and I have each carried a cell phone. Who do our kids call when they are in a bind? Me. Who does my wife call? Me. I also have to be available 24/7 for the 911 folks to get in touch with me, and while that could be handled by a pager, it is not nearly as efficient as a cell phone - a dialog with the dispatcher is more productive than a page. With two personal phones and my work one, we "float" one with the kids (usually the deaf one) all the time and situationally float my wife's phone with whichever kid might need it.
As of earlier this year all 4 kids drive, so I'm thinking about a pre-paid emergency phone stowed in all the cars. Meanwhile, some of the vehicles have older model cell phones and chargers in the glove box as "911 only" phones - that is supposed to work, but we have not had any reason to verify that so far.
I think MommaBear is correct about text messages. Since switching to tri-mode phones, we have found text messages to be extremely reliable even when there's not enough bandwidth or continuous coverage for voice. With a deaf kid in the family, we use a lot of text messaging so we waited for a super deal on a huge monthly block of TMs and added it to our contract. Some phones are more difficult to compose a text message on than others, though, and the predictive text built into some phones will NOT stay turned off (very annoying), so check out the exact model in the store before signing up. And text messaging will not work in the few remaining anlaog only areas, so it's not a panacea.
If I was only concerned about calling out for help, I don't think I'd carry a cell phone. The incoming calls are why I carry one. There may be "disposable" pre-paid cell phones avaialable in the near future and that may be worth another look for emergency kits.
Regards,
Tom