To follow up the item from a few minutes ago:
When a president speaks on live TV in a moment of crisis, he should be prepared to do one or both of the following things:
1) Announce some solution, plan, change, initiative, or other specific effort that will address the source of public concern.
2) Explain the problem, or set a mood for coping with it ("we shall fight on the beaches, we shall fight on the landing grounds.. we shall never surrender"), in a way that changes the public's outlook from what it was before the speech.
If a president doesn't have the ammo to do either of those things, he should not bother. Thus, unfortunately, President Bush should not have bothered to make his statement this morning, which essentially re-stated the arguments he has presented before that did not suffice to stop the panic. Let's hope for more real action over the weekend.