If you were at church this morning, July 9, you heard Kristin reference the work of Walter Wink. Here's more information about his work.
I'm happy to see that the work of Walter Wink is still in print. I find his writing very easy to understand, especially for a theologian delving in deep. If you want to read the book that had such influence on me, it's Engaging the Powers: Discernment and Resistance in a World of Domination. Chapter 13 gives a list of historical times when nonviolent resistance has worked to overcome oppression on a geopolitical scale. Chapter 9 contains the information on The Sermon on the Mount's section on turning the other cheek, walking the extra mile and giving up our clothes as resistance texts, not let people walk all over us texts.
Wink has also written a shorter (and less expensive) book which looks like it covers similar territory: Jesus and Nonviolence: A Third Way.