The same CAT-5 wiring that interconnects a home computer network can distribute line level (un-amplified) audio signals to multiple zones and serve as the backbone of a whole house music system. CAT-5 wiring, known as Category Five [also available as CAT-5e (enhanced) or the latest Category Six], cannot be used as speaker wire, but is capable of carrying line level analog and digital audio and control signals, even video. CAT-5 wiring is also capable of sending audio over long distances with little loss, so it's a good solution to consider if you already have a CAT-5 network.
The lyriQ system from OnQ legrand sends line level audio signals to an in-wall keypad with built-in amplifiers. The amplified keypad, which connects to a pair of in-wall speakers, also controls volume, selects source and other functions.
There is one glitch: you can't use the same network to carry computer data and audio at the same time. If you want both, you'll need two CAT-5 cables, something to consider if you're building a new home or retrofitting an existing one. A common solution for wiring a home is a set of bundled wires known as structured wiring available in many configurations to handle audio, video, control data, security and other home systems.