Can we cut out cable tv now? You might not know what Ubuntu is and even if you do, you may not associate it with TV, but nevertheless Ubuntu TV made its debut at the Consumer Electronics Show in Las Vegas today. First things first. Ubuntu is generally considered the most popular version of Linux, the open-source software that powers most of the Internet and a lot of the other gadgets, utilities and industrial processes. In addition to that, Ubuntu produces an operating system adapted for laptops and desktop computers that's similar to what you'd see on an Apple or Microsoft-powered machine.   (The name derives from a Southern Africa philosophy that espouses caring and friendship).