Sasha Volokh has some interesting legal perspectives on Zacarias Moussaoui’s acting as his own lawyer. So far he’s displayed almost no understanding of the federal legal system, has accused the judge of being mentally deranged, and generally made himself look as guilty as possible by making winking references to "his brother in Islam" Osama bin Laden.
Still, unless there’s enough medical evidence to prove that he’s unable to act in his own defense, he has the legal right to self-counsel. It’s possible that he could be found to be incompetent, but until such a ruling is made, this bizarra spectacle is likely to continue.
Still, why Moussaoui was granted a civilian trial is beyond me. If Padilla can be declared an enemy combatant, Moussaoui certainly could have been. Adding the fact that he is not a United States citizen and is suspected of being the closest to the 9/11 hjackers of anyone caught so far, a military tribunal would seem to be more fitting for his case.