I've put things away somewhere that they'd be safe from the cats (or if I don't want my DH to realize how bad I've been). Usually the only way I ever find them (if I'm lucky) is to try to figure out where I would put that thing if it was in my hand again. I'm a very imaginative person when it comes to hiding places which can be really frustrating.
I'll be cleaning somewhere and suddenly come across something that I've completely forgotten about. My DH just laughs and says it's like another Christmas for me.