Emergency & Safety User

If you plan on using your cell phone strictly for emergencies or to alert friends or family members when you're egregiously late for dinner, there's really no need to invest in a monthly service plan or a costly phone. Instead, plenty of service providers offer prepaid plans that are bundled with inexpensive phones ($50). The only drawback is that if you don't use up your allotted minutes--or dollars, in some cases--within a certain time period (usually three months), you lose them.

Cellular Phones

For infrequent emergency use, there are many free or very affordable phones that will serve your needs. You will want a phone with the ability to transmit in analog (since digital coverage is often poor in remote areas). Also, make sure to pick a phone with a battery standby time of at least 48 hours so that you'll have plenty of "juice" to make calls if you're away from a power source.

Service Plans

When reviewing service plans, it's important to make sure that you will have service in the places where you might need to use your phone. Examine the coverage maps and verify that the highways and roads you drive on frequently are covered. Many plans geared specifically toward safety users offer a modest number of anytime calling minutes for less than $30 a month. Be wary of plans that don't offer analog service, which is available in many remote areas where there is no digital coverage.

If you really want to limit your budget and usage or give your family member a cell phone for emergency contact, you should seriously consider a prepaid plan.

Accessories

To make sure your phone is always charged, consider tossing a car charger in your glove box or carrying an extra battery in case yours runs out of juice. You'll be prepared for any contingency, whether on the street or in your car.