Advocates for preventing swine flu transmission are suggesting a hand bump instead of a handshake. Fine. But in my mind, this presents many questions and the huge potential for social dilemmas and discomfort.

We all know the hand bump, seen often on the athletic field. It’s bending the arm at the elbow and raising the wrist to knock knuckles with a similarly close-fisted colleague. That works well on the football field as an expression of mutual acknowledgment for a job well-done. ...