Especially the SD cards. I just bought a half dozen new cards because I've misplaced so many of my old ones, and the new cards don't even come with a little plastic case. (OTOH, they have gotten so cheap the class 10 cards cost less than I used to pay for class 4s, and class 4 are almost disposable) Do you use some kind of a wallet? Maybe just dump them loose in a pill bottle? And in any case, do you label them somehow?
I should go look in my camera case, the lost cards might be in there... Now where did I put the camera...