Analog switches are a solid state alternative to relays, when you want a smaller, lower-power technology that won't wear out mechanically. And, as the name implies, you can use the Adafruit ADG728 1-to-8 Analog Matrix Switch to connect between eight analog signals, much like a set of 8 mechanical switches. These chips tend to be tiny surface mount parts, so this breakout will let anyone use the ADG728 switch for signals up to 5V, without fiddly soldering.