IGX

http://www.amazon.com/The-End-Money-Cou ... 650&sr=8-1

Great book, focuses on modern challenges of cash and coin, the history of monetary systems (and the history of them devaluing), counterfeiting, seigniorage -- what govts make after printing/minting costs, and the seeming diretion of moving towards a electronic based cash system.

Fun, lots of facts, though I feel this subject is changing so quickly that the information already seems a little dated (book came out in 2012).