You Could Look it Up: The Reference Shelf From Ancient Babylon to Wikipedia
This is a fun book for anyone who's interested in facts and the acquisition thereof. (And if you're not one of those people ... why are you here?) You Could Look it Up is itself a bit more than simply a collection of facts--it's not itself a reference book. Jack Lynch has the ambition of structuring his work around a question: what is it, through written history, that people have felt that they needed to know but couldn't keep in memory? It's no real knock that he doesn't fully succeed; it's a big topic.
This book will appeal to fans of Simon Winchester, for obvious reasons. It also reminded me of this, although You Could Look it Up is better.