I was at a talk by Col. Chris Hadfield when he mentioned a problem with space sick bags. He said that when you use a space sick bag, without the force of gravity to hold what's come up down, it has a tendency to bounce off the bottom of the bag and float back to the top. Not ideal.
I was thinking about that while trying to get back to sleep last night, and I realized that the solution might be to redesign the shape of the bag. If you were to indent the bottom of the bag (with, say, a v-shape), anything bouncing off it would be reflected not directly back at you but off to the side.
Of course, it could still ricochet off the side of the bag and come back to you. To discourage that, you'd want to taper the sides in. Make the bag more triangular.
Doing that, however, still has its disadvantages. Without gravity, up and down are arbitrary. A bag which tapers out from the top, considered upside-down, is a funnel. To prevent that, you'd want a shoulder at the top. Or, better yet, a tube going partway in. (You need a valve to close it off anyway, right? If you make that tube a little longer, you're fine.)
But then... a triangle with a notch cut out of the bottom seems familiar. And, come to think, having that notch be asymmetrical could have some advantages. And, really, why not have fun with it if you can?
I present to you what, to the best of my late-night figurings, is honestly the ideal shape for a space sick bag:
The Starfleet logo.
It'd cost a little more to manufacture, but it just might be worth it.
(I sent a copy of this, without the crude diagrams, to NASA. It'll be a couple of weeks before they can reply, but I'm interested to hear what they make of it.)