Maybe it’s just me, but everybody seems tense on the streets here in Manhattan today. It’s hard not to be. Our local news has been filled with images of people buying duct tape and plastic sheeting. There are more cops on the street. I walked past a midtown synagogue this morning, and saw barriers around it, and a policeman standing outside. The Post and the Daily News both blare the same headline: SUICIDE ATTACKS. People are waiting, waiting. Down on the subway platform at 51st and Lexington, the place was filled with people, and everybody was … silent. No kidding, people stood stock still and grim. The only sound, aside from the approaching train, was a lone man, a panhandler, singing “Amazing Grace” for tips. One was not comforted.