Man, my PSK is packed so tight that nothing would dare try to rattle around in it! I'm talking about my Altoids pocket tin version. My bigger pack-oriented version (based on a Nalgene water bottle) has a bit more room but even that baby's packed pretty tight and I've never noticed any rattling. But in that bigger kit I have the needles, fishhooks, etc. bundled together with fishing line so the group isn't really subject to rattling. Your magnetic tape idea sounds pretty neat for kits that are not crammed full to the gills though!