Overall, security planners said they have learned a great deal about how to prepare for the inauguration through their experience in dealing with other major events since the Sept. 11 attacks. Mason said there have been numerous "tabletop" exercises to consider various possibilities attended by officials from all the key agencies, something that did not always happen in the past.
"It is in our minds to be as unobtrusive as possible and still get the mission accomplished," Mason said. "This is the people's event. That's what it's all about to me."