Don't put the guitar pick between your teeth when you don't need it for a sec.
My bf plays the guitar, and was working on recording a song, so he put the guitar in his lap and the pick beween his teeth while doing something on the keyboard. Some saliva went down wrong, he coughed... and swallowed the pick, which got stuck somewhere halfway down on the way to his stomach.
He ended up spending Saturday in the hospital getting it removed, which involved such fun things as X-rays, full anaesthesia, and getting stuff shoved down his throat. He quite scared everyone, even though it wasn't really all that dangerous. I don't want to thing about the option of this getting stuck in his windpipe.
There's a lesson to be learned from this... But I'm not so sure bf learned it. In bed that night, he was telling me that, all in all, it had been a pretty good day - after all, the hospital had been more uncomfortable than dangerous or painful or nasty, he'd gotten to play around with his new recording equipment, and got to spend a quiet evening with me instead of working from 1 to 10pm (he'd've gone in for the late shift - 5-10pm - but he wasn't allowed to because of the anaesthesia). He's probably the only person I know who'd refer to a day mostly spend in the ER and having emergency surgery as "a pretty good day".