Weird sqeaking noise. HELP!!!

I have a squeaking noise that is coming from my truck only when I move. At idle it makes no squeak what so ever but as I progressively accelerate is gets louder. Its really annoying and I checked my serpentine belt (didn't take it off ) and it seems fine. It doesnt stop when I hit my brakes either so I assume its not that. It sounds like a belt though......... What could it be?????? Help me out fellas

 

when was the last time you greased the u joints? start there

 

+1. ^ Only when you move? Are you sure you dont have a U-JOINT going bad? Is it a constant squeak or does it sound rotational? The fact that it gets louder as you accelerate....Have a volunteer sit in the bed of the truck and see if they hear it from under the truck. Good luck.