If you live in the US, you're probably familiar with recycling drives where used cell phones are collected and donated to soldiers, battered women's shelters, and low income families who can use cell phones to call 911 even without a service plan.

In other countries, used cell phones also help disadvantaged people. The most interesting case, is, perhaps, North Korea. With closed borders and food shortages, surviving is more than living off the land. Used cell phones allow citizens to place calls outside of the country, allowing them to do business with the Chinese. They help North Koreans evade eavesdropping on their national network. And, of course, because used cell phones are affordable, they're helping an increasing number of North Koreans to have these tools.

Of course, you can do good with your own used cell phones. Just make sure you recycle them, so other disadvantaged people can use cell phones, too. Plus, you're keeping them out of landfills and making sure that rare earth metals get collected.

In fact, you might be able to get paid for your used cell phones, Buy Back programs like Cash 4 Phones are a great way to get rewarded for passing along your used cell phones.