In March of 2006 my wife Mary and I owned about 3,500 books. We both have eclectic interests, voracious appetites for knowledge, and a great love of used bookstores. The problem was that we had no idea what books we had or where any of them were. We lost books all the time, cursed late into the night digging through piles for that one book we knew must be there, and even bought books only to find that we already owned them. There were books on random shelves, books on the floor, we were tripping over books when we walked up and down the stairs. In short, we had a mess.