How many different cellphones have you yelled into in your lifetime? I remember singing the praises of my bag phone with the battery life of a tse-tse fly. Since then? Dozens. And they were all useful for as long as they lasted and the next big thing came along. For all I know, they're still useful to someone, somewhere; they all worked perfectly when I got rid of them. No wonder there's a huge market for used cellphones, and it spans the globe:
It's the Circle Of (Battery) Life. Read it here.