Disclosure: I received complimentary products to facilitate this post. All opinions are my own.
If you've ever taken small kids on a road trip, you know how often you have to stop - and you know how urgent it sometimes is, especially for the little ones. Emily Baldwin developed the Number One Cup out of necessity as the mother of three sons. It was designed to be easy to use, even by small children. It has finger grips to avoid slipping and messes, it fits in cup holders, and it is sold with several hand wipes to help with hygiene. Her boys not only tested it, but helped design it, with a kid-friendly take on the skull and crossbones idea to make it clear this is not a cup for drinking. The cup is made in America and is BPA-free - a version for girls is currently in development.
Honestly, I can definitely see how this would come in handy, even if the idea is a little disgusting. I know my mom has told stories of she and her siblings doing their business in a coffee can in the back of the station wagon when rest stops were few and far between, especially in certain areas of the country. I think the cup is designed well, with features to minimize the ick factor as much as possible. The lid fits tightly, with no leaking, and the hard plastic makes it easy to wash. It could definitely come in handy!