Today, Ed Ballinger will speak to a roomful of strangers about the one subject he doesn't care to discuss: The first two hours of his shift as a flight dispatcher for United Airlines on the morning of Sept. 11, 2001. The Arlington Heights resident and former United Airlines employee will meet with a sub-committee of the 9/11 commission in Washington, D.C., so panel members can decide whether his testimony warrants his appearance before the full commission. Ballinger is there because he was in charge of United flights 175 and 93 when they crashed into the World Trade Center and a...