The role of derivatives in the current crisis?

[BushSpeak]

Around two years ago Warren Buffet expressed concern about the volume that derivatives had attained - around ten times the global economy. Something like 500 trillion against 50 trillion.

Of the 500 trillion, 10% was attributed to housing loans and subprimes, but 80% was being played in the world money markets. That's 8 times the world economy.

Is it possible that derivatives could be the hidden hand driving the the current crisis? At least someone is making a killing on the misery of others.

I would appreciate any information/links that explain how derivatives could be profiting from the current crisis.