I think we should have packs of hundreds of trained German Shepards roaming the airport without supervision. That way everyone would get screened by someone who knows what they are doing, and all bags could be screened by our four footed friends as well.

If someone sets off a doggie's nose alarm, the dog would simply immobilze them in .3 seconds. If someone ran away to get a camera, some of the pack would chase and tackle the idiot, ripping out his or her throat. We wouldn't have to shut the terminal down.
This would also cut down on cost.

Instead of hiring people to operate expensive machines that they have no idea how to operate, we could hire half as many people simply to scoop poop in the terminal.
No need for pimply, sexually frustrated 18-year-olds with machine guns.

This is, of course, a joke. Although more trained dogs and handlers would drastically cut down on screeing costs and make screening more effective.

Additionally, few things in life are more chilling than a German Shepard. We have a nice 90 pound alpha female. She is a sweetheart who licks us to wake us up every morning, but just the sight of her scares the living bejeezus out of everyone but my immediate family or those she knows well. Plus, she could probably break any bone in my body with one bite, so I'm kept in line. I'm also pretty sure that the she prevents any potential home intrusion better than any gun or security system.

I do think dogs are grossly underused in airport security. Ask a K-9 handler how useful his or her dog is.