hmmmmm cabincrewboy, just like my Compass Mk1 headsets (and many other one-jack headsets!). But that was long ago when I was young and irresponsible. Now I mainly collect playing cards (BA's are good), writing sets, pens, airline mags, toothbrushes and other items which you don't actually have to steal. (OK, you don't have to steal used cardboard boxes, you just need to be desperate! Or enthusiastic? Although I must admit the QF dot patterns inside the boxes are cute.). And, probably like you, I never use my souvenirs, just look at them and remember when and where they came from.
Although, I must admit that, in the days when PanAm put trays of miniature after shave and perfume bottles in the toilets (much more hygienic than the open-top big bottles), my pockets used to clink with tiny bottles of Onyx a/shave as I left the aircraft. Man, I smelt good for months. Somehow menus and sleepmasks aren't quite the same!
But emergency cards - that's low-life.
"...every aircraft is subtly different.."