IMO, the most effective way to avoid terrorism in US is to change it's foreign policy (like bombing Kosovo and so on).

But I guess this is not going to happen, so check out some other suggestions (many already mention by other FTers):

- OK for carry-ons and small blades, since cannot control them;

- Check-in only by trained personnel using www.truster.com or similar solution. Interview must be in english or local language. Speakers of any other language must show up hours in advance, for interview in mother language by teleconference.
If unable to communicate, no flight. Exception to profiled people with special needs;

- Pilots, FAs and ground personnel submitted to Truster on daily basis;

- Passport even for domestic flights;

- Iris or fingerprint check at gate, connected to a worldwide database. Persons not yet profiled must register prior the travel date. If no record or discrepancies, no flight;

- An uniformed security officer part of every crew;

- An armed air marshals in street clothing every flight;

- Martial arts lessons to every crew;

- Strong cockpit door, that can be open from outside only after some seconds delay. During this time, pilots can lock from inside if something is wrong;

- Closed-circuit camera over the airplane, including cargo compartment;

- Some sort of "sleeping gas", activated from the cockpit, that put everybody asleep until the pilot lands in safety. Ground security must then concentrate on masks and breathing devices;

- All information regarding flight, including images, transmitted to ground real time. Don't rely only on black boxes;

- Study some ways of intervention from ground, including tele-piloting if necessary;

- And, for us FTers, learn a martial art.

Love to you all,

Toxa