I don't know how many times I've been buying a used lens in a shop(yes, amazingly enough we have two great ones within a block of each other) and after paying for it asking "can I get a cap for that?" Since I'm rarely buying anything other than a Nikon brand lens, the shop that sells new stuff usually goes to the back and hauls out new Nikon branded caps-and yes that means the really nice current front caps with the big pinches areas in the middle. I still seem to end up dumping my bags every few weeks since the front caps for the lenses I'm using tend to migrate to the bottom. I will say that I'm particular about using rear caps and body caps, although it's not that common for me to carry a body without some sort of lens attached in a bag(and I'll qualify that by saying one of my more used bags has a narrow, tall compartment in it where I can fit a a bare F2 or F100 perfectly, so one or the other is usually there if not an FM or FA). I don't use my Leica that often, but I admit to being incredibly conscious of the lens cap. I've lost shots on other rangefinders(long before I had the Leica) but I'm also paranoid about burning a hole in the shutter. It's actually the only camera where I've ever used an eveready case since loading film on screw mounts is an involved affair anyway and I feel like I'm striking a reasonable balance between protecting the shutter curtains and not forgetting the lens cap should I want quick access to the camera.