I uploaded the talk:
"You Do Not Know the Work of the True God Who Does All Things"
-It was given by Geoffrey Jackson (of the Governing Body) and has good experiences about not underestimating the value of the preaching work we do. And to remember that even if we don't always see the results, Jehovah is on top of things, and in control, and he can maneuver matters which we aren't even aware of. One of the experiences (at the end of the talk) was also related by him at the Long Beach International Convention, which I posted awhile back here (it's the last experience at the bottom of the post).