Some more:
No wisdom teeth as of yet (25, so there’s still time before I officially say I don’t have them.)
I can also put both feet behind my head…and I"m a guy. I can’t keep them there for more than a few seconds, though. Funny story, I got a concussion in college from demonstrating this ability.
Me, too. I did not know there was a term for this and have always jokingly referred to it as being semidextrous.
I write, knit, crochet, and use a needle with my left. I use pliers, scissors, and paring knives with my right, but a bread or carving knife with my left. I fence left-handed, but use my right hand for racquet sports and throwing. I swing both ways, though (in baseball, you pervs!). When I use an eye pencil to apply eyeliner, I do my left eye with my left hand and my right eye with my right hand. Same thing with mascara and eye shadow.
I used to be able to write cursive backward with my left hand – and very fluently, too. I probably could do that again with a little practice.
I’m not sure if this counts, but when I touch my belly button it makes me need to pee.
I also used to have *something * I could move with my hand at the bottom of my ribcage on one side. My Dad told me it was an extra rib I could move up and down, but frankly I’m pretty dubious about the old mans assessment there. Whatever it was, I grew out of it eventually and nothing movable remains.
Damn, hon, there’s only so much room on the back of the baseball card, y’know?!
Perhaps your situation is the same as mine…He told me that it happens sometimes, and there’s nothing too bad about it…at worst, it has the potential to create more back problems in the future, but I haven’t had any since my last visit there.*
Kids, don’t carry heavy backpacks. I learned that the hard way.*
**On the other hand, the carrying of heavy backpacks did lead me to discover about the extra vertabrae in my body. 
There’s lies, damned lies and folks with extra limbs
My ears produce more wax than the average candle factory.
I have Duane’s Retraction Syndrome. Long story short: I can “cross” one eye. My left eye does not have full range of motion, and is slightly recessed. I can look forward and to my right just fine, but looking left results in my left eye remaining in the forward position, with my right eye turned to the left.
Incidentally, my left eye also has poor vision, and my right eye does most of the the work. Luckily, or perhaps as a result of the defect, my right eye is dominant. As a matter of fact, I often times see much better when I close my left eye. This is especially true right after I get up in the morning or late at night when I’m tired.
Dammit, it’s Duane, not Duane’s. Sheesh.
How you doin’? 
I also have no wisdom teeth. I passed this on to my daughter. No idea about my sons. The dentist said I was one step higher on the evolutionary ladder than most folks. I tend to use this in restaurants and the like–I find it gets me better service.
I had wisdom teeth, but 2 of 'em came in facing the tooth in front instead of up. One was so rooted-in it had to be chiseled into 8 pieces to extract.
Also, my thumbs go out of joint when extended, and can’t bear weight for very long. And I sweat like a beer bottle all year round.
You’re a man, probably with more muscle than flab, and maybe with dense bones. Most men are negatively buoyant; women tend to be positively buoyant. Being overweight can affect that (more positive). (I sink like a stone unless I have a lungful of air).
Although I grew wisdom teeth unlike the rest of you oddballs, I still have my wisdom teeth. And room for more. My dentist was amused. And then he looked at my jaw x-rays, and told me to never come to him for oral surgery – my roots are down to my jawline, apparently. :eek: He did fix my teeth-too-close-to-floss problem, though – he drilled my teeth apart. Glad he did it, but if he’d’ve told me first it would’ve freaked me out of doing it.
I have no patellar reflex. Tap my knee with the little hammer all you want and all you’ll get are bruises. This gave my pathophysiology instructor a fit of giggles.
The spaces between my outer canthus and my auricles are extremely short. My eyeglasses always took a lot of tweaking to fit me.
My ear canals are very short and straight like a very young child’s. I was used for the pediatric ear exam part of the assessment lecure when I was in RN school.
I have a pair of supernumerary nipples just like in the picture here. My cousin has three extra nipples and my uncle (his dad) had 2 extra pairs.
Great, now my ring is stuck halfway down my index finger.
I don’t have much to offer. One of my co-workers found a survey on health and flexibility that got everyone doing different stretching tricks, where I found I was significantly more limber than just about anyone else in the office.
Oh, and when I was getting fitted for a bicycle, I learned I have a shorter torso and longer legs than the average Dane (the sizing chart was from Danish bike maker), and that my right arm can extend abnormally longer than my left (I chalk this up to surgery I had years back to repair a dislocated left shoulder).
I don’t have patellar reflexes either. I forgot to put that on my list. It freaked my pediatrician out when I was a kid. He kept hitting my knee and nothing. My sister doesn’t have them either.
Recently Mom was telling me “you know, Your Nephew has the weirdest indexes, they curve in a lot… I know I’ve seen it somewhere but can’t remember…”
I flattened my hands one the table top and said “like these?”
“OH! Well, gee, guess he definitely is your nephew, in case anybody had doubts.”
Our pinkies are more curved than usual, too.
I have one more rib on left side than on my right. One of my verterae didn’t form fully on the right side, so it’s wedge shaped. The left side is perfectly normal and a rib protrudes from the vertebra like normal, but the right side…isn’t there, I guess, so no rib.
As a result, my whole upper torso is kind of out of whack, but it’s really minor. No one noticed anything was wrong until scoliosis screenings in elementary school. My shoulderblades stick out at different angles and my left shoulder is slightly higher than my right.
My right foot is more than one inch shorter than my left.
My left leg is about a tenth of a cm shorter than my right, which caused a few problems when I was younger, but I adapted long ago.
I was alergic to water as a baby and had to be washed in olive-oil. Mum says sea water cured me, but I was too young to remember any of this.