Magical storage containers
Another supreme space-saving device - think the terrific trunks from early Resident Evil outings: Thing goes in box. Thing comes out of any one of a dozen other identical boxes. It's like having your own personal wormhole network, except with perfectly defined slots for everything to go into. And a box on the outside. And probably no capacity for safe personal transport. Hey, stop making all these outlandish demands, okay!
In our minds, though, the boxes only seem really useful when exploring creepy old houses built by puzzle-obsessed eccentrics, as the need to carry around armfuls of crests, keys, passcards or other such obstacle-clearing devices seems not to extend into real life situations. Though we'd bet such boxes would be perfect for smuggling smut into the house without brown paper wrapped packages giving the game away.
Infinite time to form response
"I, um... ah... but if you..." Stop! Aren't you sick of having to come up with everything you say at the moment you say it? Wouldn't life be much easier if every situation prompted you to choose from a selection of appropriate phrases, while allowing you as much time as you needed to select the cleverest, pithiest or most suitable response? Of course it would!
Even better would be if we knew what the other person's choices of response would be to our responses, making it possible to chess-move our conversational 'opponents' into uttering phrases that fitted in with a response we knew was coming up in our own selections soon, and so make other people's responses part of our own response in order to respond only to the responses we felt able to respond to.
Which works out far less complex than attempting to give the 'right' answer to classic bear-trap questions like "Is it me?", "Did you take it?" or "Do I look fat to you?".