Okay, since we're on the topic, I have a slightly tangential question... How do you make one-way magnets? Or can you? I dismantled a hard drive a while back, and the two magnets inside pulled VERY ...

I was recently gifted a charming, kitschy magnet, and as I tucked it into my wallet for safekeeping, I couldn't seem to remember: Do magnets spell doom for credit cards? Many of us have held onto ...