Many years ago, a man I went on a couple of dates with gave me an audio CD of sermons from Tim Keller at Redeemer Presbyterian Church in NYC. I have maybe thirty or so and have ordered or downloaded for free, other sermons or audio programs from Redeemer that I have found extraordinarily helpful like their talks on Christian marriage and how to make it work.
This morning on my iPod, a sermon related to the scripture reading this week, Blessed are the Poor came up. I don't think I'd ever listened to it and found it to be a revelation in understanding what most most people of means don't, what poverty does to the individual and society at large and also how Christ views His special relationship to the poor. I just looked it up and the sermon is free, so I'd encourage you to pick it up.