My friend was doing some cutting with his circular saw. He propped the blade guard open (danger danger). After finishing a cut, as the blade was spooling down, he stepped into the blade. At first he thought he wrecked a pair of shorts, but a second later the blood really started flowing. He ended up slicing open his thigh, missing his "hammer" by inches. At the hospital, the wound ended up being over 6" long, and 1" from the carotid artery. Lucky for him the cut was not into the muscle, or tendons. He took 50 stitches and is laid up for about a week. I think he's pretty lucky, he could have lopped of his "hammer" or cut the artery (not sure which would be worse. Hope this inspires you, as it has me, to be extra careful with our saws.
Matt