I've been reading The House of Morgan in all my free time lately. I highly recommend it in general, as a well-written biography of sorts. In fact, it's a string of biographies as it works its way through the lives of the various J.P Morgans, et al.
It may be a truism that history repeats itself, but this book shows precisely the lessons we learned and forgot again. The dangers of unregulated financial markets, the fiscal and political power held by banks, the extent to which banks can capture the business/industrial world--all of these themes and more were present before 1929. The repeated panics of previous 50 years resulted in nothing but more power for banks, even after the Federal Reserve System was created. The American banks governed their debtor companies, created trusts (remember U.S. Steel?), made it possible for England to win WWI and Germany to pay its reparations and rearm.
It makes for eerie and fascinating reading. As an antidote, I also picked up Steve Martin's autobiography, so we'll see how it goes.