I received a complimentary copy of this sermon from Grace To You, John MacArthur's online ministry, about two months ago. The CD is titled, "A Christian Perspective on Work." It is really awesome, and I've listened to it on my way to work several times since receiving it.
Today, as I was searching for something else, I came across the same recording online here. The GTY website calls the sermon "A Theology of Work, but the content is exactly the same. You can read the entire transcript or download the sermon and listen to it for yourself if you'd like.
Hands down, this is the absolute best treatment of the topic I have listened to. It really is a treasure. Check it out.