I'd appreciate any opinions/info available on whether a rumor I heard is true or not. I just learned that US bills, $20 and above, have a magnetic strip embedded in the bill, on the left hand side. Looking at the front of the bill, under the "U" in United States, it's clearly visible on those bill printed in 1990 and thereafter. Supposedly, bills in the $5 and $10 amounts have started being fixed in such a way. Now...the interesting part. The rumor is that it is possible to detect, at a modest distance, the existance of and the amount of currancy being carried. Thus, if a person boarded an airplane carrying $12,000 in cash in a money belt, it would be possible to detect that fact. The rumor expands that this has in fact already been implemented at one airport (at least). Any thoughts?