If you're putting together a multi-room audio/video system that involves longer cable runs between rooms, check out the Niles C5-HDDA. This clever device uses durable, inexpensive CAT-5 cable to send standard- or high-definition component video and digital audio signals to another room in your house. It's a great option for homes with an existing CAT-5 network, since you won't have to install any new in-wall wire. And it delivers crisp, detailed sound and high-def video, even over cable runs of up to 500 feet.

How it works
You'll need to purchase two baluns to set up a fully functioning system. You can use two C5-HDDAs, or pair one with an in-wall model. Connect the first one to a satellite receiver, high-def disc player, or other A/V source in your main room, and plug it into a nearby CAT-5 outlet. Next, connect your second C5-HDDA to a CAT-5 outlet in your remote room. Then hook it up to a TV and A/V receiver via its component video and coaxial digital audio jacks. The compact C5-HDDA doesn't require AC power, and it's wall-mountable for flexible placement.

What is a balun?
A balun gets its name by converting signals between balanced and unbalanced lines. Balanced cables can carry signals over much larger distances than unbalanced lines, because of their superior noise rejection. The C5-HDDA balun converts audio/video signals between balanced CAT-5 connections and unbalanced component video and coaxial digital audio connections.