I can twiddle my thumbs in opposite directions (so that, for example, your left thumb is rotating clockwise and your right thumb is also rotating clockwise). Most people can’t; at least, not easily.
I can levitate small, spherical objects (half-consumed jawbreakers, grapes, olives) using my own breath. Keep 'em levitated about two inches above my lips with my head tilted backward for a few seconds or so until I run out of breath. Really wowed my friend’s 9 and 11 year old daughters at a wedding a few months ago. Yeah, I’m a class act.
Arrgh!!! Damn you!
Can you elaborate on this a bit more, or did I miss the joke? When you say “stick a fork in my left arm”, do you mean stab yourself with it and just let it stay in?
I can program myself to wake up at a specific time. I use an alarm as a backup, but if I don’t have an alarm, I can fairly reliably wake up at the specified time.
Heh heh heh. Tough, isn’t it? 
There is a secret to it:
[spoiler] If you are doing it properly your thumbs will cross twice per rotation. Ignore trying to make them twiddle in opposite directions and just try to make them cross at the “top” and “bottom”, and gradually you will get it.
Then you too can drive folks nuts with this totally useless accomplishment! :D[/spoiler]
Most people can do it a bit, but what I consider flaring is usually a lot bigger, and I know few who can do it.
I can sing the names of all the states in alphabetical order.
Alabama
Alaska
Arizona
Arkansas
California
Colorado…
etc
I can stick out my tongue and touch my ear.
I can jump over a broom stick while holding on to it. You know, through my arms.
I used to challenge really tall basketball players (I’m 5’6) to a jumping contest.
I knew a girl in grade school who could do the cloverleaf thing- way cool.
I can wiggle my eyebrows independantly, although I can’t make them do a wave thingy.
I can occasionally guess a person’s birthdate. Sometimes I just know what it is, without ever having actually learned it. It kind of freaks people out, especially when we’ve just met.
I can wiggle my scalp (without using my hands, of course). Kids love it because I have a big mess of curly hair, and it looks funny when I make it move.
Lost4life - your EAR? How? I can lick my elbows, which some people say can’t be done… but your EAR? I am in awe.
I’ve got the tie the cherry stem in a knot inside your mouth thing down PAT!
(Control yourselves, ladies…) 
I have minimal eye-hand coordination and my left elbow was busted so my left arm ain’t worth shit. Yet anything I throw with my left arm will hit its target.
Use the force, Annie.
Note that Lost4life did NOT say he could touch his ear with his tongue. He said he could stick out his tongue and touch his ear. I believe anybody can do that! 
I can ride a bicycle while sitting backwards (sitting on the handlebars and feet on the pedals). Learned it in the course of a day as a kid and never forgot how.
Me too, and can do the nostril thing.
This is my normal state. I use an alarm clock only when there’s a plane to catch.
My coworkers were very disgruntled when I mentioned this.
Like many others, I can wiggle my nose, my scalp, both ears (at the same time or independently), raise just my left eyebrow (but for some reason not just my right, I’m working on it).
I can also tie a cherry stem in a knot with my tongue. It’s a good party trick, and not nearly as difficult as you’d think.