If someone opened my beer with this Klein Bottle opener, I'd probably yelp in fear. It looks so alien and just plain weird that I can't believe it actually works.
Here's what Bathsheba Sculpture, the company behind the Klein Bottle opener has to say:
The problem of beer: That it is within a 'bottle', i.e. a boundaryless compact 2-manifold homeomorphic to the sphere. Since beer bottles are not (usually) pathological or "wild" spheres, but smooth manifolds, they separate 3-space into two non-communicating regions: inside, containing beer, and outside, containing you. This state must not remain.
A proposed solution: Clearly the elegant course is to introduce a non-orientable manifold, which has one side and does not divide 3-space. When juxtaposed with the beer-bounding manifold described above, it acts to disrupt the continuity thereof, canceling the outdated paradigm of distinction between interior and exterior. This enables the desired interaction between beer and self.
I'm not even sure if that's English. Told you they were alien. [Bathsheba Sculpture via Neatorama]