This is one of the greatest inventions I've seen in a long time. Using a charge in the saw blade, if it detects capacitance from human flesh it immediately halts and retracts the spinning blade. When pushing wood through at any reasonable speed, it's supposed to stop before the blade cuts any deeper than 1/16th an inch. Probably does irreparable damage to the saw's blade, but at least you keep your fingers.
Not that I have any use for a table saw, but if I did, I'd buy this one, more reviews here.