(Won't mention excruciating hip pain if I sleep on an air mattress.) ;)

Wonder why that is? I do better on the ground than on an air mattress.

I can touch my eye (again - years of contacts).
I can do the one knuckle bend on all fingers, though it looks weirdest and most broken on my index finger.
I have over-extended joints, so I can bend my thumbs and fingers way back.

I can also crack my neck and back, wrists, elbows, knees and ankles without touching them. Although the most satisfying neck crack is hand assisted.

I can't roll my tongue or touch the tip of my nose with it, but I can tie a knot in a cherry stalk. However the sexiest way to do that is to hide it up in your cheek first and only pretend to put the straight one in. Then you can maintain eye contact throughout and only make minimal mouth movements. Doing it for real can make you look like you have something stuck in your teeth. And if you cheat, so what? It's an advert for a blow job and I doubt any guy is going to call Trading Standards ;)