"Yes, but apparently a lot of other actions against the US were prevented during this time, presumably using the same intelligence gathering/sharing systems."

Oh, agreed. They stopped lots of stuff they knew to look for, mostly things that didn't require as much cooperation or imagination. For instance, in the case of the Millenium bomb plot it only took one attentive border guard. No special intelligence work was required, just one low level civil servant being curious enough to search the guy's car. That guy deserves a promotion, a raise and a reward (though knowing my luck, the guy who replaces him at the check point won't be as curious).

Don't take this wrong, but if Ben Laden were more like "Pretty Boy" Floyd, the FBI would have caught him long ago. Ben Laden's a new thing and, regretably, large, complex institutions change slowly.