Don’t leave out the thumbs: my thumbs are ‘double jointed’, i.e., I can pop the second joint inward while bending the first joint over. In other words, it looks sort of like a dog’s ear. I could make really cool finger guns that other kids were jealous of, and do cool shadow puppets with the ear thing. yeah, but it’s not as cool as the finger thing…shit…
Yep! I’ve grossed out just about everyone I know with it; I’ve never met anyone else who could do it. But I have a little “extra” with it: my left index finger, when i bend just the top joint, has the two tendons (over the middle joint) really pop out at attention. I’ve had people cautiously touch them and jump back, saying, “oh, ewewewewEW!” 
What’s really cool is winning bets that I can put a penny between the tendons, flex the top joint, and slowly rotate my finger so the penny is stuck between the tendons when it’s upside down!
Let’s see, I can also:
– (with pulling from the other hand) pull my thumb up and put it on the top of my hand and have it stay there (imagine the tip of your thumb resting on the top of the first joint of your index finger).
– pop my shoulders and hips in and out of their sockets. This isn’t all that great (besides for freaking people out, heh), because I’m only 21 and I can’t sit on the ground for more than 5 minutes without having to move around because my hips start to ache badly, and sometimes my shoulders just bother me for “no” reason.
– my right ankle can pop in and out when i flex my foot left-right-left
– my elbows hyper-extend. I still remember ballet when my teacher said, “straighten your arms above your head as much as you can!” and then seeing me said, “not a Y-SHAPE! EW!”
– if I rotate my wrists repeatedly, each time around they make a crunching sound.
– my second and third toes of each foot are double-jointed (the top joint can bend backwards).
– the usual thumb-to-wrist, Vulcan sign, etc.
– I’m pretty damn flexible. I can take my left foot and touch my left hip with it (same with my right foot), which apparently looks painful to many.
I can do all the fingertips except the pinkies. Maybe I never practiced enough with them.
How to: straighten out finger(s); this is done by pulling from the back of the hand. Keep pulling; add a pull from the down side of the finger (meaning the palm or inside-of-the-curve side); watch tip bend. Practice for improved style.
Does this mean those who haven’t been able to, can now acquire this valuable skill? Some who have never been able to bend the tip, with this description can you start to do it?
I can do all of my fingers like that (besides the thumb) obviously.
Only on my left index finger, which was broken at the second joint and fused. I can only bend the second joint backward, which is great for grossing people out
I used to be able to bend the last joint when I was a kid, doesn’t work anymore. And I assume i haven’t been able to for a long time.
I can do it with both my index fingers - I lock the middle joint and bend the top one, so I can point round very small corners!
I can do it with all my fingers, individually or together, or several in combination. I can also bend the middle joint of each finger without flexing the last joint, and with difficulty do this and the bend-the-last-joint-only trick at the same time with different fingers. I can also bend my fingers backwards somewhat in an arc, about an inch above the back of my hand at the fingertips. Two inches if I push with the other hand.
Yep, I can do that with all my fingers. Individually, all at once or anything in between.
It never occurred to me to try bending the middle joint while leaving the last one straight until this thread, but it turns out I can’t do that one.
I can do all of the above but I have ehlers stanlos (genetic disorder that affects joints)
I’ve been able to bend the first joint only thing since my mom showed it to me in second grade. The interesting thing about doing that is how the distal joint then gets all loose and rubbery, as if the tip of the finger is no longer attached to its tendons.
I can do it with the index and middle fingers of both hands. My husband can do it with all ten fingers.
Here’s another trick: hold your hand flat and try to bend just the second joint of your pinky and nothing else. When I was little my dad made me think this was a special talent. I’m not sure it really is.
Edit: wait. By “first joint” do you mean the one nearest the hand or the one nearest the tip of the finger? My first line of this post refers to the one nearest the tip. My second line refers to the one nearest the hand.
Second edit: NEVER MIND, I found the rest of the thread :rolleyes:
Wow, no one bothered to comment on the fact that this thread is from 2003!
Okay, I’ll go ahead and make the obligatory comment:
Can zombies bend the last joints of their fingers? 
I can pick things up and using a pencil print in large block letters to things
another ehler danlos person here, there are variations of ED that as you get older can cause really serious health problems, like with your heart, so please do keep that appointment and stay in touch with you doctor
you might want to go read this message
http://boards.straightdope.com/sdmb/showpost.php?p=16213407&postcount=56
that level of flexibility (and the pain you are describing) makes it sound as though you might have ehlers danlos, a genetic disorder. there are variations of it, but some can affect your heart. There are treatments that help. I wish I had known when I was younger, i’m in my 40 s and somedays have to use walkers or wheelchairs because I didn’t know to get it looked into
I can bend the tip of my fingers, not pinky or thumbs, though. I can do it about a 90 degree angle. Yeah… I’m weird
I can do this with every finger - bend them at a 90-degree angle.
I can also move the little toe of both feet without moving any other toe/part of my foot.
i can only do it with my index fingers fully, but i can have my had at a 90* angle and i can so it (so, added together, i can have 1 finger on each hand go 180* past what i think normal.)(*=degrees).