If you've got time for a terrific sermon (about 45 minutes) and if you'd like a relevant, thoughtful and biblically-centered perspective on how the Church should be impacting the surrounding culture (instead of the other way round as is happening in the emergent church and seeker-friendly movements), then I couldn't recommend more highly "The Watershed of the Evangelical World" by the incomparable Francis Schaeffer.
If you don't have the time to listen, at least read through this pdf file containing the basic points of Dr. Schaeffer's sermon.
The sermon link comes from blogger Lane Chaplin who says, "it’s one of the best sermons I’ve heard him preach."