I agree that safety of others should be taken into account when
deciding to break the rules and bring along an i-pod during a race. I
would have no problem with someone listening to music during the run
because the risk of harm to others is minimal. However, being able to
hear during the bike is crucial. Racers will often warn the biker in
front of them that they are going to pass them on the left for
example. If that biker could not hear the warning and suddenly moved
to the left (to pass another biker for example) there could be serious
conscequences. I would be inclined to turn in a biker who was a
danger to others. During Ironman Arizona 2 years ago, I almost ran
into a biker on a cell phone for this exact reason