Except for the scalp thing, I can do almost everything mentioned so far. Which means that you’re all a lot more normal than you’ld like to think, or that I am King of the Freaks.
Personally, I’m leaning towards the latter. Bow before me, peons!
I could do that (including William Tell Overture, though I had no idea Curly did that!) until I grew a beard. Tends to muffle the sound. However, I still can do musical tongue clicks, quite quickly.
And then there’s the one talent that I rarely share, because I’m invariably asked to repeat it for friends, and their friends, and so on: I can perform “Stars and Stripes Forever” by making rhythmic farty sounds with my lips while simultaneous humming or clicking my tongue.
I used to be able to put my whole fist in my mouth. However, I just tried it for the first time in a few years and either my hands grew or my mouth shrunk. Now I can only get it in up to the knuckles.
Yeah, that last line sounded pretty dirty.
I have an eidetic memory - if I read something once, I form a mental image of it and can recite it almost entirely from memory (limited, of course, to a few paragraphs. I’m not that good.)
However, if I’m studying, I just rewrite my notes on paper with a cool pattern - likes clouds or rainbows or what have you. I can vividly remember the pattern of the paper and then the words just appear with it. Makes studying a piece of cake.
That’s all for me. I bow to the King of Freaks, Miller. I always knew you had it in you, baby.
I can make almost real sounding chicken noises.
I can raise one eyebrow (Spock-like). 
My feet don’t match. One is noticeably bigger than the other when I place them side-by-side.
Not really a talent, but still kinda freaky.