PLEASE read this link before the JPM hearing tomorrow... I went to the local laundromat several months ago and chanced upon a stunning article in the the June 1, 2009 Issue of "The New Yorker". (OUTSMARTED: High finance vs. human nature. by John Lanchester) which I have linked below.
The article explains how JPM has been directly involved in worldwide economic meltdown and subsequent destruction in the value of the US dollar by creating the now-well known devices which allowed them to eliminate risk from their spreadsheets while, at the same time, making money from these devices. A MUST READ IMO!!!