I finally made it to The Book Thing in Baltimore after hearing about it, reading about it, and thinking about it for several years. Today was the day of action.
In the Saturday afternoon traffic of this gorgeous 72 degree F day, it took me about an hour to get there, door to door, but it was easy to find and very much worth the trip.
The approximately 150,000 titles are organized by subject, such as History, Children's, Classics, Mathematics, Christian, Fiction, Family, Education, and so on, and they are all free, free, free! Yes: free!
The books are not alphabetized by author in their respective sections, but I wasn't expecting them to be. It's not really the place to search for a specific title/author, anyways. It's more like a treasure hunt.

The Book Thing welcomes donations of books. They are especially in need of quality children's books, evidenced by the few that were available in the bins on the floor, and the many ecstatic children gathering them up by the handful. I plan to take a big boxful next time I visit.
The Book Thing wants you to take away as many books as you want. In fact, they strongly encourage you to...
While I browsed, I was treated to the breeze flowing through the open doors, and the pealing bells of St. John's Episcopal Church across the street:
I must say that I did feel a twinge of guilt as I left with my small armload of treasures without paying. Something about it didn't feel quite right. Especially since I feel I scored big:
The stack, from the top:
The Shack by William P. Young. Looked to have never been read. I tried to read a borrowed copy a few months ago, and couldn't get through what I thought were the first few badly written pages. I even told friends I couldn't read it, but there it was, free. And some of my friends said they were greatly impacted by the book. So I guess I'll try again. Or pass it on to someone else who wants to read it.
Field Guide to the Piedmont: The Natural Habitats of America's Most Lived-in Region, from New York City to Montgomery, Alabama by Michael A. Godfrey. This was marked with Book Crossing stickers, so I registered my finding of the book and made a journal entry.
Captains Courageous by Rudyard Kipling. A 1964 edition with lovely illustrations by Charles McCurry:
The Graphic Bible: From Genesis to Revelation in Animated Maps & Charts
by Lewis Browne, 1929. We'll use this book in our home education, probably daily:
The real score, though, is this Van Loon's Geography: The Story of the World We Live In by Hendrik Willem van Loon. It's a 1932 (seventh printing) edition, inscribed by the apparent one-time owner, John H. McQuilkin, Midshipman, U.S. Navy:

I already own a copy of this book, but it's not nearly as large and beautiful. I will treasure and use this book frequently with my children. Does taking this particularly good copy when I already have a perfectly acceptable one make me a selfish hoarder? I don't know. I hope not. I do know that I would gladly pass on my other copy. ~grin~
I'll be going back to The Book Thing soon...with a good selection of children's books to donate, and my eyes peeled for new treasures.