»In which we drink from a Kleinsche Flasche

For many years I was not an adherent of the television program "Futurama", although it fit my "A"-list criteria: animated, amusing. Now that I know how many nurdalicious maths jokes the show has, I am eager to watch it. A Klein bottle has neither inside nor outside; it is a closed, nonorientable surface of Euler characteristic. Legendary sysadmin Cliff Stoll makes these "One sided, boundless, and mathematically nonorientable" bottles for sale, as well as steins after the same fashion; one could indeed drink from a Kleinsche Flasche!