You've probably heard this one, right? A guy invents a technology--called SawStop --that prevents a table saw from causing the major causes of worksite injury. An electrical signal passed through the blade senses any contact with flesh and immediately locks the blade. (Even if you get it, go to their website and watch the hot dog video.)

Sound good? Well, not good enough that the major manufacturers think buyers would pay for it. It's an unfortunately world where market competition means that nobody will pay a few extra bucks for revolutionary safety features like this.

After failing to license the technology, they have actually started to sell products directly themselves. They're a bit, um, expensive though. Bummer, since mass production would certainly bring the costs down...