Acme Klein Bottle. This site also has a comprehensive description of a Klein Bottle.
See this YouTube video for an excellent visual construction of a Klein Bottle.
Because the computers at Berkeley were not isolated, but networked to other scientific and military computers, the hacker could potentially threaten our national security. Stoll skillfully draws us into his world of trying to find the hacker, get the proper authorities involved, with varying degrees of success, and prevent the hacker from getting sensitive information. Through the story, I was able to feel Stoll’s frustrations in dealing with the bureaucracies, the thrill of trapping the hackers, and the tedium of setting up traps.
Despite that this was first published in 1989, the damage a hacker can do to any networked computer and the need for secure passwords described in “The Cuckoo’s Egg” is as valid today as it was then. Most of us don’t have military secrets on our personal computers (at least I hope we don’t), but we all do have some private information that we wouldn’t want compromised. Even though I’m a reasonably experienced computer user, this book reinforced what I knew about the need for my own security as well as informed me on certain issues that I had not given any thought, and it did so in an interesting and humorous manner. Even though there were no high-speed chases, no explosions or fires (well one, sort of, but I’ll leave that for the reader to discover), this was a thrilling page-turner. Recommended.