Food and Shelter
You can survive without water for about three days, and without food for up to a month. But in a city, you probably won't even have to skip a meal, as long as you can get your hands on money.
It's a great idea to fold and tape a $100 bill to the removable plastic cover of your phone's battery compartment. If you lose your wallet, cash is always nice.
Another way to get cash is to get it wired to you from your spouse or someone else back home via, say, Western Union. (Use GOOG-411 to find the closest office.) ID is generally required, but if you don't have one, you can simply give the money transfer number (which Western Union assigns the sender).
You can also survive without cash by checking into a nice hotel. The better the hotel, the more of your survival needs can be met without actual money.
Hotels always ask for your credit card and ID when you check in. But they don't really need it. Most hotels are willing to accept credit cards over the phone. They often tell you that it's against their policy. But explain your situation, and they'll probably do it. If they absolutely refuse, then find another hotel.
Once you've found an accommodating hotel, just have your spouse or someone else with a credit card call the front desk while you're standing there, and the hotel can process the transaction over the phone.
After you've checked in, your chances of survival increase exponentially. You can eat by ordering room service, and bill other services, such as car or taxi service, to your room. (Arrange all this through the front desk.) You can use the computers in the business center. Importantly, the hotel gives you an address to which your spouse or someone else can overnight credit cards, clothes or anything else you may need.
You need to survive in the short term with food and shelter. But you also need long-term survival, which means you may need to get some work done. The most important thing for many people is the ability to send and receive e-mail. So make sure your phone can get work e-mail via an installed application or an online e-mail service.
One of the most battery-saving ways to send e-mail through a phone is with Jott, a free service that records your voice and transcribes it into text, which you can send to yourself or to your contacts. By setting up contacts in advance, sending e-mail becomes just like leaving voice mail.
You can also use Jott to update Google Calendar, just by talking. Incidentally, it's a great idea if possible to use Google Calendar or some other online calendaring site, or at least synchronize your regular calendar with one of them. That way, you'll always be able to access your business appointments no matter what.
You can also find computers in hotel business centers, airports and in random locations at cybercaf
You can also use services like SugarSync to gain access to literally all your files and data. But you'll have to subscribe and set it up in advance.
Getting Out Alive
Airport check-in and airport security need to see your identification before they let you fly, so how can you get out of the city without ID?
The little-known truth is that you can fly domestically without it. (In fact, there's an entire blog devoted to flying without ID.) Just make sure you arrive at the airport earlier than usual -- three hours before your flight is safe -- and explain your situation both to the check-in desk and to Transportation Security Administration (TSA) people.
They may resist and deny your request, but they'll almost certainly accommodate you eventually. TSA will probably subject you to additional screening. But remain polite and persistent, and you'll get your boarding pass and make it through security and on that airplane home.
This story, "Cell Survivor: Conquer a City With Nothing But a Cell Phone" was originally published by CIO.