Diversion Safe, Diversion Safes, Can Safe, Can Safes, Water Bottle Safe, Brief Safe, Underwear Safe, In-Home Security
Some of these could work for smaller items. (money, rings, etc) Not the pop cans or any bevaerage containers because cleaning staff could mistake them for garbage & throw them out... but the hairspray can or shaving cream can (or dirty undies like someone already posted! lol) could work!
Vacation Vault | Keep Your Valuables Safe
My friend has actually purchased one of these "vacation vaults" but I'm not sure how it went. She planned on bringing it to the pool in her beach bag with her & leaving it in her suitcase in the room.