Leonard Sweet is the leading futurist for the evangelical church. Check out AquaChurch 2.0: Piloting Your Church in Today's Fluid Culture.
Tom Sine is another excellent futurist. Check out his books:The New Conspirators: Creating the Future One Mustard Seed at a Time and Mustrad Seed vs. McWorld.
Culture and the Church
The best articualtion of how to discern this is through "Structure and Direction," as articulated by Al Wolters in his excellent book, Creation Regained and also articulated in Brian Walsh and Richard Middleton's The Transforming Vision.
Here's a quote from Walsh and Middleton: http://stevebishop.blogspot.com/2009/09/structure-and-direction.html
There is an increasing understanding that the gospel of the Kingdom of God is more than just sharing the Four Spiritual Laws. It is a holistic redemption of all things that God created. The gospel is that "Jesus is Lord" over everything, which would have to mean that he was serious in Luke 4 when he says he is preaching good news to the poor, proclaiming freedom for the prisoners and recovery of sight for the blind, releasing the oppressed, and proclaiming the year of the Lord’s favor. This is humanitarian, and it is gospel.
Gabe Lyons and David Kinneman's book UnChristian does a wonderful job articulating this. You've probably already read it. You should subscribe to Gabe Lyon's online resource, Q Ideas - absolutely essential!
Also, the latest issue of Prism is all about evangelism as it relates to social action, which makes sense since this is the magazine from Ron Sider's Evangelicals for Social Action!
Humanitarian work is a major component of the Missional Church. For my D.Min, I'm reading Alan Hirsch's excellent book The Forgotten Ways: Reactivating the Missional Church, and he has an online assessment tool for churches to help them see how truly missional they are: http://www.theforgottenways.org/mpulse/