Well, I'm noticing a trend around here and I'll take that idea a step further. My kids can't even be in the same room as something that they don't want to play with.
Example 1: I'll go to get the kids out of room time and find a pile of little things that they've stuffed under their door that they simply DID NOT want in the room anymore. They couldn't just NOT PLAY WITH IT! They had to push it out of sight.
Example 2: If we give one of the kids a tissue before putting them to bed we KNOW it will end up in the hallway within a few minutes of closing the door. As soon as they're done with it they'll go over to the door and push it underneath into the hallway. It's not just a tissue though. They can't just NOT sleep with a "friend" or a blanket or a toy that was left in their sleeping room. They will try to cram it under the door NO MATTER HOW BIG IT IS!
This is what just slid under the door a few minutes into naptime today=)