Why is it that you if you place your hand palm down, fingers spread on something, you can lift all fingers alone except the third (next to the little finger). Wha on earth is that about?!?!
I can lift all mine too without any movement from the others. Something else to try is to spread your fingers with the second and third touching and fouth and little finger - then change to third and fourth touching...
I can lift mine too - but something I can't do. Clench a fist and straighten each finger individually, 'til the finger is extended roughly parallel to the back of your hand. OK for each finger except the third one. (BTW it is acheating to hold the others in place with your thumb!)
The trick with this is that you should have your middle finger curled under your hand, so the first joint is almost vertical. Then you can lift all fingers except your ring finger. Even if you hold it up and try and keep it up on muscle power, when you let go it will drop again. I think it is to do with the way your tendons are connected in the back of your hand (as paulz said).