What Technology Could We Not Live Without?

At one time there were questions about whether microwaves were healthy. There was speculation that cell phones were causing brain cancer when they first became popular. Both are believed to be untrue now, but what would happen if a major piece of technology that we depend on on a daily basis was found to be unhealthy? Would we be able to give it up? Not just use it in a different way, but give it up completely. We already know that cars are unhealthy, but not too many people have stopped driving as a result. Because cars are unhealthy on a global basis rather than an individual basis it's hard to appreciate the cause and effect. But it if was something more personal?

I looked around trying to think of what technology I absolutely couldn't live without and I think it would be a sad day in who-ville if I had to give up my computer, well, to get even more specific, email. I know it's ridiculous, but what if the day came and bam... no more email (and no more text messaging since it's basically the same thing.) What would happen?