While better screening of pax is an option, it is more of a problem with international flights. If I fly over to the US and want to make internal flights, will I have be registered on some central database? To be honest, I can see the introduction of global citizen registration being one of the long-term effects of the September 11th attack -- and if you're not registered, you don't get in to Europe or America. Even longer term, this could be the start of the World State, with all that implies for terrorism and our personal liberties (which, after all, we are trying to defend). Don't forget that any such tools are potentially vulnerable to compromise and corruption by terrorists.
We will never be utterly safe from attack, no matter what precautions we take. For me, that's an acceptable risk in return for the benefits of aviation and as a pax I'm prepared to accept responsibility for following the rules and not adding to the risk through stupidity or selfishness.
Security is everyone's business, and I hope that message is made clear in the aftermath.
R