This Christmas, there were nearly 7 million new Android and iOS activations, which means we're going to guesstimate that there are also now approximately 7 million out-of-service cell phones lying around. (Give or take.) If you got a fancy new tech item during the holidays this year, it stands to reason that you now have an older, unused counterpart sitting around collecting dust. How about donating, recycling, or even exchanging them for some cold hard cash?