Around 2008-2009 I discovered that Project Gutenberg, which is one of THE best sources for free, out-of-copyright books, was suggesting that people can volunteer for producing those books. I signed up. I became a proofreader for the aptly-named Distributed Proofreaders. The system is long and beautiful and it produces the excellent books on the Gutenberg website today (I can tell you all about it later). It was a lovely period of my life.