Well the sound is getting worse. I took the car to Midas to see what they could find. Although there is a warped flange on the rear manifold, that's the least of my problems. The sound is coming from inside. I put a stethoscope on it while they had it up on the hoist, and there's a really bad knocking that is coming from inside the motor. It seems to be loudest around the number 1 cylinder, and louder up toward the top of the block vs. the oil pan. I'm now thinking spun main bearing, loose connecting rod, or a long shot maybe the timing chain. Here's a quick video if anybody wants to have a listen.
http://www.youtube.com/watch?v=nMBUrlmmPuU