The sheep mentality of "hijackers threaten, we cave" is gone forever. If I'm on a plane and a hijacker tries to take it over, I'll take a bullet or risk getting blown up before I let that plane be crashed somewhere. I am not exactly the most fit person in the world (I have an arthritis-like condition in one hip), but if I can get in the hijacker's way long enough for someone more physically able to take him out, it would be worth it.

Next, ban carry-on luggage. Make the potential hijackers carry their weapons on their person rather than concealed in their bags. The amount of luggage people carry with them onto airplanes is ridiculous. Okay, so maybe you don't ban *all* carry-on luggage - but you certainly ban this stuffed-full-to-the-brim crap people bring with them. One item, briefcase sized or less. Max.