I want to invent, like, the opposite of a water balloon. A cheap container that will hold a vacuum, or at least very low pressure air. I could sell them on eBay as your own personal void to scream into.

We used to go to a restaurant called Mongolian Barbecue that was like this. You were given a bowl and you put all the veggies and meat you wanted in it in one bowl and sauce choice in another. Hand it someone behind a counter working 6 woks and they sauté the veggies and finish with the sauce. I fucking loved that place.