Rear end squeak under acceleration

When in drive there is a loud annoying squeaking that seems to be coming from the rear end. It doesn't happen in reverse. It seems to squeak faster than the wheel rotation but does speed up as I accelerate. At first, I thought it was brake related but it still squeaks under braking. I'm thinking it may be rear end or drive shaft related. The sound doesn't seem to eminate from inside any housing. Any ideas?

U-Joints...:2cents: