Cable spaghetti refers to the common mess of wires found under most computers and audio/video equipment. It's the result of each signal being carried in a lowest common denominator connector. A common example in the computer world is that practically every device that plugs into the machine requires a separate cable, and in the audio world each channel of audio, left in, left out, right in, etc., requires a connector.
Cable spaghetti can be reduced dramatically by using better cables. For instance the use of ADB on the Apple Macintosh meant that there was only a single (chained) cable for the mouse, keyboard, joystick and other similar devices. Modern systems use USB which can have a similar effect, but USB devices often require their cables to be attached to a hub, which has only a marginal effect on the problem. USB's true advantage is that it allows less used devices to be removed when not in use. Apple continues to try to solve these sorts of problems, with their latest machines combining power, monitor and USB signals into a single cable.
In the audio world there have been a tremendous number of attemps to provide a single cable containing left and right stereo in and out signals in a single cable. Older Pioneer Electronics systems often include a small round 4-pin DIN jack for this purpose, but so few devices supported it that they eventually gave up on it.
Today the problem is only made worse by the addition of video cables to the mix, and that most systems have considerably more components. Whereas a record player and cassette deck were likely the only two components found up to the 1980s, today's systems typically add a CD player, a VCR and a DVD.
