It is the story of Luis Soriano, a teacher who decided to start a travelling library. He carries his books by burro to remote villages and farms in Colombia.
Here is a YouTube video of a report similar to the one I saw a while back:
Here is the update from the first video:
Based on Luis' story, Jeanette Winter has written a children's book that is available for advance purchase from Amazon. The official release date is coming up on June 8, 2010. It looks like it will be a great addition to our growing Colombia related library. Here is a link to Amazon where you can see a sample of a few of the pages and order the book.