I have to point you to an amazing site I recently stumbled across: Faith By Hearing. Be sure to check it out! From the site:
"Soft words produce hard hearts,” says John MacArthur. How true this is. And the preaching that comes from many modern, man-centered churches is soft and unable to tenderize the stony hearts of men. How urgent it is that we find godly preachers who have a high view of God and a high view of Scripture.
Faith by Hearing is designed to collect and categorize the ever-growing availabilty of great Reformed and conservative evangelical audio preaching & teaching that has a high view of God and Scripture. This is not merely a machine gun listing of sermons and lectures (though it may seem like that at times.) This is a personal project to encourage others to be blessed by the preaching and teaching of godly men who are faithful to the all-powerful Word of God."
On a side note, I love the header graphics of John Owen, Martin Luther, and John Calvin making good use of their ipods. :)