Also, for table saws, there's SawStop. This is expensive, about $1500 for their table saws (made in USA), but protects you from lost fingers. Table saws cut off about 4,000 fingers a years in the US. SawStop has a system which detects a touch to the blade by anything conductive (such as a finger) and fires an explosive charge which jams a stop into the blade, stopping it in half a tooth of rotation. This costs you about $150. TechShop has these, and they get about two emergency stops a year.
I'm 100% against these in a serious shop. The reason? Most of my tools are dangerous. Bandsaw? Yup. Lathe? You bet. Drill press without a guard on the belt? Yeah, lost some hair to that, built a guard.
You get the idea, tools need to be treated with respect.
I don't like the idea that one of them, that is dangerous, is now not dangerous. That tends to make me let my guard down and I don't want that to bleed over (pun intended, sorry :) to the other tools.
If I could make them all safe, that's a different story.
A friend has one - only time it fired was when he forgot to deactivate the safety mechanism and tried to run aluminum through the saw. Bam!
Not trying to piss on the technology though — great if it saves someones fingers. SawStop the company though is douche-ish (you can Google it to see how obnoxious they have been).
Bosch too now have a similar safety mechanism on some of their saws.
I have seen these, but the place that I know locally that has one, has never had the SawStop piece fire - however, it is very good to know that it is there, and the manager in charge of the wood shop feels very relieved about having it.
Apparently wood dust—the invisible diesel-exhaust-like particulates, not the stuff you can see—is also a major health hazard, and will progressively destroy your lung capacity if you let it. A rubber mask with proper particulate filters is called for, as well as one or more forms of local or general extraction.
I'm surprised most of these sites don't mention this.