In a conference honoring Milton Friedman's 90th Birthday held in 2002. Ben Bernanke, already one of the Fed's seven governors, told Milton Friedman, "Regarding the Great Depression, you are right, we did it. We are very sorry. But thanks to you, we won't do it again."
That is from an excellent piece done by Grep Ip in Wall Street Journal on the developments of Ben's views on monetary policy, read it here.
Here is another related piece by Ben praising Milton Friedman's work on monetary policy.