Oh wow, that would get my goat. I'm "fanatical" about preparation and memory. My misses often misplaces items, because she puts stuff in different places all of the time. It is very simple when you look at the human brain: find a place to put something and always place it there. Period. I promise this works. I've been working with the kids on this because everything from tape to pencil sharpeners. Drives me bonkers! LOL

Here are two articles that may be of interest:
http://www.wsj.com/articles/SB10001424052702304117904579501410168111866

and

http://www.quickanddirtytips.com/productivity/organization/how-to-stop-losing-things

Creatures of habit. So consider a two fold approach: 1) have your loved one begin placing things in the same place all of the time, and 2) invest in a keyfinder product such as:

http://www.amazon.com/KeyFinder-wireless...5WQCD0GFN0WYNFT

OR:

http://www.amazon.com/Click-D2-Receivers...5WQCD0GFN0WYNFT

This second one I believe is slightly louder than the first product.

Good luck. May patience be with you smile