I spend an absurd amount of time working in the mobile development space, and I have more than a little interest in using the mobile network for emergency communications.

In the United States, mobile telephony service is fair to poor in general within urban and suburban areas, and poor to non existent in rural areas.

There are effectively only 2 networks with what approximates national coverage, AT&T's GSM based network, which has more physical infrastructure (towers) than Verizon, but because of the GSM network architecture, is more prone to dropping calls, and the Verizon CDMA network, which has a more stable call-handling capability, and thus less dropped calls. Both Sprint and T-Mobile are far behind ATT and Verizon in terms of network coverage.

That said, no matter what your network, texting - which uses the "control" channel of the network - will get through where voice calls won't. This is true no matter the carrier and/or underlying network system, and this is why it's never a good idea to cancel texting service on your phone - it might save your life.

In terms of phones, it's a huge tradeoff between battery life and functionality. Anything with a touch screen - an iphone or any of the zillions of android based smart phones - is going to be hugely useful on the one hand, since they are super-powerful computers that happen to make phone calls and send text messages, but that power comes at a huge cost in terms of battery life.

For many years I carried a Nokia 1100 - a phone that I'd charge every few days, a phone that made more than one trip through the laundry , and a phone that was often in my pocket on fire scenes. Any "candybar" form phone with a small, simple screen is going to have great battery life. I like any of the LG brand phones - they have great software and exceptional battery life.

I currently carry an iPhone 4, but I also carry a small LG 100C phone, it's got 10 days of standby time and 2.5 hours talk time. That's a prepaid from Tracfone and the underlying carrier is Verizon. That's how most of the prepaid companies, except Metro PCS work - they just resell minutes from the big carriers. Many prepaid carriers run on the smaller networks, I recommend only Tracfone as a prepaid company, it uses AT&T and Verizon. The LG 500C and 800C are also good, but the 500C is going to have better battery life than the 800. (the 500 has 9 days standby, compared to 8 days for the 800).

All smartphones share the following set of really handy features:

- GPS
- Camera
- Local Data Storage
- Phone Calls
- Text Messages
- Email
- Web Access

Unfortunately there are two features that most Smartphones lack:
- Waterproof
- Shock Resistant

The Motorola DEFY is one, but as far as I can tell, it's only on T-Mobile, a carrier that only works within 150' of the center of the top 25 urban areas in the USA.

That's the only one I can find in the USA, there are others in the UK and Japan, but they won't work properly here.

Waterpoof cases for smartphones sort of help but they really make the phone cumbersome.

So, despite these drawbacks, I DO carry my iPhone basically all the time. When I'm working in the yard, I wrap my iphone in clear plastic wrap - keeps the sawdust out of the charging connector and keeps any mild water spray off it - and the touch screen works just fine.

In terms of charging, I have a solidus solar charging rig for pretty much anything, including the iphone, plus AA battery to USB port devices that help keep things charged up.

But in the end, I think that any Android or iOS device is going to give you all of the features you could want, and then some.

Oh, and one other thing - I've been using a Galaxy Tablet of late in a test to see if I like it better than the iPad, and I have to admit that I kind of like the Galaxy Tab a lot - more than I thought I would, and as a "tricorder" for today, it's actually quite a bit more useable than the iPad.