Popular Mechanics does a terrific job of debunking the Katrina story. I seem to remember they did a marvelous job of bursting the 9/11 conspiracy believers' balloons as well.
Cited for Breaking the Christmas in Cambodia story (at Kerry Haters):
Hugh Hewitt: KerryHaters was on this story a long time ago. How could the elite media not have asked these questions before now?
Ankle-Biting Pundits: Our friends Pat and Kitty at Kerry Haters deserve the blog equivalent of a Pulitzer for their coverage of Kerry's intricate web of lies regarding Vietnam.