In the last year, I’ve been to Finland (where I bought a temporary SIM card for my three-day trip there). I also have SIM cards for Iran, Estonia, the Netherlands, France, the US, Senegal and others. But once I get home, these SIM cards are useless to me — they sit in my desk drawer. I’m sure there’s hundreds if not thousands of other people worldwide who have a stack of SIM cards that they don’t use much, but keep on the off-chance that they do return to those countries.
For example, today, I lent my Dutch and Finnish SIM cards to another English assistant who is going to those countries over the Christmas break. Both have < 10€ of credit on them (assuming they haven't expired), and I can't use them at all as I have no plans to go to either of those countries anytime soon.
And that got me wondering -- why isn't there a website/service, analogous to CouchSurfing or something, where I can temporarily borrow/swap a SIM card that I only need for a short time (say, a week or less), without having to pay much for it, or go through the hassle of buying a new phone number/SIM card. Before I came to France, I bought two used SIM cards on Craigslist in the Bay Area, and boy am I glad that I did, because new ones (at least from Orange) cost 15€ just for the card.
So, any enterprising web developer up for the challenge?