Something that you can build on vacation in no time, having no tools and no materials.
1. A coaster.
2. A cork.
3. A pair of scissors.
4. A knife.
No matter how simple it looks, it’s a full-fledged sphericon made from four halve-cones, even though the cones are hardly visible.
And as for any sphericon, its center of gravity stays on the same level all the time, so it needs just a slightly slanted surface to roll.