Ok, so I finally found out how to reproduce this frickin crank noise. First, I will describe the sound:
When you have an ungreased thread, and something is screwed in tight, then days later you loosen it. Sometimes it will make this "metal-rub-loosening" noise, like a quick "pang!", its a mix between that and the sound you'd hear if you threw a penny at an aluminum frame.
Now here is how I reproduce the noise:
I stand on the pedals, with the crank arms parallel with the ground. I wait a few seconds, maybe ten seconds. Standing up, with my weight like that. Then I will quickly move the crank about an inch in either direction. NOTE: *It is not the play in the rear hub, I am sure of that* It's not the play in the hub, because I know what that is like, and it's NOT it. But I can feel a small jerkish-vibration-quick thing in my feet via the pedals when I hear the noise.
I have no idea wtf this noise is, but it just doesn't sound good. I didn't grease the inside of the BB spindle, but when I screw in the crank bolt, there is this little grain-ish stuff inside the spindle that makes a grinding noise when tightening the bolt. That is my only lead, except I dont' think the bolt would fricken move, since any pressure is on the splines when you pedal.
Anyone have any idea? It's either the crank, or the chain I'm thinking.
Oh, and if I feel it vibrate in my foot, could it possibly eliminate the BB or crank, and problem lie in the pedals?