Does it have to be one that I suffered or saw? When working as a firefighter I had gone to three chainsaw accidents. In each situation, the chainsaw laid open the thigh...down to the bone, and there was no blood. In the first case, the guy walked 1/4 mile back to his house to call 911, we walked the 1/4 mile to check for blood loss, there wasn't any.

Hard lesson for those guys? If the cainsaw is too heavy, stop cutting, set it on the ground, and walk away.

I was usuing my little Makita to put together some small plywood boxes, and was holding the screw as I was getting it started.....the makita slipped and the head dug into the bed of my thumbnail...it was rather unsightly, the nail got all messed up, and three years later, it's still a bit soft on that side.....but it was fun showing all the boys my wound >grin<

didnt happen to me, but did to a girl in my highschool..

we had a set construction class, we built the sets for the plays.. stupid girl didnt tie her long hair back before using the table saw.. yes, you know what happened next.. big chunk of hair got caught in the blade, and instead of turning the table OFF immeadatly, she reared back, and a big ole chunk of hair and scalp came off and landed on the table.. EEK

My co-worker at a machine shop got her arm sucked into a drill press and turned into black and blue hamburger covered in a shredded layer of greasy long johns. Mmmmmmmm.......
careful.

Once, in a fit of intelligence, I knocked myself in the head with a hammer while trying to remove an industrial staple from a fence. Right after that, I discovered the joy of Vice Grips & cat's paws. Not really a "power tool" unless human-powered tools count.

As far as real power tools go, I've mostly seen the aftermath of other peoples' accidents...legs cut up by jigsaws, underarms (and hair) leaned too close to table saws, and of course the inevitible slag-in-the-pants-dance-into-something-heavy that using a cutting torch brings from time to time.

OH crap -- how could I forget my "favorite" experience with a long series drill bit?! I was on a job where the manager was really bad about providing equipment. I was living on a sailboat and didn't have my own tools with me, so I ended up using his, including a horrible pair of goggles that were not only scratched all to hell, but they kept fogging up on me as well. Anyway, I'm putting in the railing to a deck 3 stories up in Twin Peaks, SF when my goggles went foggy on me and I couldn't see the drill point I'd drawn. I put my goggles up on my forehead for a moment, got my point...and then forgot to put the goggles down over my eyes before I started drilling. YEEEEOOOOOW! Of course I got a huge chunk of crap in my eye.

Because I was alone by the time it really started to bother me, I drove myself to the hospital, yowling all the way. When I got to the ER, I just flat-out demanded to see someone, which happened after I endured a couple of minutes of hospital paperwork. Lucky for me, it wasn't Saturday night. They gave me eye drops and vicodin, so at least the night wasn't a total loss. On the upside, I've never forgotten my goggles since.

As a heavy equipment operator, I get to see all kinds of weird things, like people backing into cars, rigging and each other. Luckily, I'm pretty conscious of what I'm doing, and all of my equipment "incidents" have been on purpose. If you've never picked up your manager's car with a 36,000 lb forklift and placed it on top of a ship-to-sea container for fun, I gotta tell ya, it's a great way to let off some steam.

Working on a bar room after hours with a guy. Starting @ 3AM. He was using a belt sander . I was laying floor tile. I hear a BIG BANG. Look up to see all 220 Lbs. of biker Dude OUT COLD. His pony tail( which reached his butt),wound around the belt sander. Lucky for him when it knocked him out it came unplugged before it sanded his face off. It was a blonde dude moment!!!

The day I learned that feed direction is very important with rotating tools:
was in a woodshop class, using a shaper (similar to a router) to cut stiles for a cabinet door. Fed the stile into the shaper from the wrong direction, and had the 3'ft long piece of wood ripped out of my hands and rocketed across the shop at, oh, something like 60 mph. It flew clear across the shop and knocked a hole in the wall. Just very VERY glad that there wasn't something like someone else's head in between the shaper and the wall.

Coming from someone who has to practice being anal-retentive, there are some times and places where you just can't be TOO anal about how you do things...

~C

PS-- is there a hyphen in anal-retentive??