A keychain with greyed out keys (if used) would work wonders for me. I only ever toss keys if I'm a 100% sure I've used the key in question. I mena, it's not like that game tells you most of the time. It's just the one odd key every once in a while that is branded with something super specific as "Ruined Tower 2nd floor bathroom".
Agreed. For now I've been keeping a backpack in my inventory just for keys/papers, but a keychain would be awesome.
