A device that would allow anything I’m looking for to beep, like you can search for the cordless phone by making it beep, or call your cell phone if you don’t know where it is.
This is something I’ve thought about often. The way to do this is to make remote-enabled stickers to attach to any item. Then you have a remote which you program with the description of the item, and which will beep faster or slower according to location, like the hot-and-cold game. Of course you will stop misplacing things. (But heaven help the person who misplaces the remote…)