One of the great blessings of technology is the access that we now have to top-flight resources. For those who desire to learn biblical truth at a deeper level without the cost or time of seminary, you can now access tremendous content for free online. Here are two great examples:
1. Covenant Seminary Worldwide Classroom
Covenant, based in St. Louis, is an excellent reformed seminary and is the official seminary of the Presbyterian Church of America (PCA). This website has 20 courses, all of which have downloadable lectures, notes, and study guides.
2. Reformed Theological Seminary on iTunes U
RTS, where I am currently studying, has a few dozen classes, chapel messages, and conferences. Of particular interest to you Tim Keller fans is his “Preaching Christ in a Postmodern World” seminar. All of it is free as long as you have iTunes (which is also a free download here).