Twenty-four U.S. airports in four weeks might be an easy gig for a rock-'n'-roll star, but for me, it was like being on a hot LZ. Last month, I started on the East Coast and zigzagged across this great land from the Big Apple to the Needle in Seattle and back promoting my new book, "Steel My Soldiers' Hearts." My previous book tours have always seemed a bit like infantry combat – at least in terms of the wild pace and no sleep – but prior to the World Trade Center catastrophe, you could pretty much count on coming back....