I knew a guy who would finish a two liter, or other plastic bottle, and suck all the air out until flat. It may not have been perfect, but he well surpassed anything I could have done, as well as anyone else in the shop.
My own dumb but impressive trick was to toss my cigarette into the air and catch it in my mouth. Unlit of course.
I do a “Jack O’Lantern” trick where I light a match and put it into my mouth, still burning. I close my teeth around the match and grin. It looks AWESOME in the dark!
And, the time I was showing it to my fiancee in the fancy restaurant and started laughing and my tongue touched the lit end and reacted by pushing it into the roof of my mouth, burning the inside of my mouth? Not quite so awesome.
I can wiggle my ears, and bend the first joint of my thumbs back behind the back of my hand. My shoulders used to be loose enough for me to put one arm up and one arm down, and grab my wrists behind my neck, but now I can only go as far as fingertips to palms.
crack ankles, elbows, hips, shoulders and neck. All 20 fingers and toes go without saying, but knees, jaw and wrists still elude me.
lick my own nose.
Flip my eyelids inside out. Very gross looking, but much less weird than what a friend could do : he could make his eyes sort of bulge out of their sockets and vibrate like crazy. Outstandingly creepy.
So do I, but I thought everyone could. For that matter, I can also touch my elbows behind my back.
Stick a fork in my left arm or leg at picnics; usually more the biker kind. I have no sense of pain in my limbs on the left and I found it an “instant freak” to sit there balancing my plate and just stick the fork in my arm while having a beer or something.
I saw a video from an old IJA convention where a guy did a similar trick prefaced with “Kids, don’t smoke. But if you do, light them all this way”. He tossed a cigarette behind his back and caught it in his mouth, then tossed a lit wooden kitchen match behind his back, caught it on the cigarette which caused it to light.
I’m out of practice but back in my serious juggling days I could balance a chopstick vertically on my nose.
Was able to do the quarter catch off the elbow thing with as large a stack of quarters as my hand could hold (30+, I think). I was also able to flip stacks of beermats (coasters) or playing cards off the edge of a table - you put them at the table edge about halfway over, then bring the back of your hand up from underneath (strike the overhanging coaster with your fingernails). The coaster does a flip in the air and you close your thumb, catching it. I could do a full pack of cards (loose) that way.