The Moussaoui jury got it right, thank goodness. Sentencing him to life in prison accomplishes three things: it punishes him appropriately for the criminal activities he was involved with, it denies him the martyrdom he so obviously craved, and it restores confidence in America's sanity, that we are not willing to execute someone for a crime they only wanted to commit.
For my take on the trial, go here. But for a much more spirited, entertaining rant, go here.
UPDATE: The fantastic Dahlia Lithwick sums it up: Acting as a check on a runaway state, these jurors refused to allow a government needing a scapegoat and a man wishing for martyrdom to stand in the way of the facts. These jurors understood that for this country to kill a terrorist for his ideas, hopes, and dreams is not much different than the terrorist's desire to come here and kill us for ours.