Tim Challies, over at Challies.Com, used to do a series of blog posts titled "Reading Classics Together." While doing these posts, he would invite his readers to... well... read a classic together. I always wanted to follow along with his posts, but I never had the book and/or I didn't have the time to add another book onto my current reading list.
A couple of days ago he posted again that he was going to start another classic. He posted a poll for his readers to decide which classic to read, and the one that was decided upon was Christianity and Liberalism by J. Gresham Machen.
At first I was disappointed because I just don't have the funds to purchase another book, but at the end of his post he had a link to reformedaudio.org that has a free pdf version of the book and a free audio book version of the book. (Click here to go to the Machen page to download the audio book or the pdf.)
Challies is planning on starting this book on June 2. To read more about Reading Classics Together, go to his site and read this post.