Imagine that your car just broke down on the highway during morning rush hour. It's raining, and you pull out your cell phone to a tow truck--only to hear a sad chirp from your handset as the battery dies. It's an all too plausible scenario, especially for those of us who aren't so conscientious about charging our phones.

That's why we recommend tossing an emergency cell phone charger into your glove box, your suitcase, or anywhere else it might come in handy. These little cranks, battery boosters, and even solar chargers can give your depleted handset a few extra minutes of juice--just enough to call a friend, dial a tow truck, or even notify the police. We've reviewed five of the latest models and rated them for portability, ease of use and reliability. Find out which one is right for you.