Knock on wood, no 722 issues for me. Not all cellphones are equal. The blackberry and nextel seem to be the worst in the US due to the frequencies used.
FWIW, they were selling metal mesh bags pre 9-11 that you'd put your bag into and lock when flying. The idea is that the metal mesh secures otherwise unlockable bags. Maybe the mesh could be incorporated into a faraday cage for a bag?
I don't think anyone here has tested whether quad cables reject the noise better (or even sound better/worse) than non-quad but we have discussed it. I know that some of the teflon-silver cables are not quad, fwiw.