You’re in the living room with your “significant other” watching a movie or TV show or sports event on your beautiful big flat panel HDTV, and then one of you decides that you’d like a snack from the kitchen, which is the next room. Do you pause the show (if it’s a movie or you’ve got a DVR or equivalent service that will let you do that) or does the person leaving the room just lose out? If you’ve got a TV in the kitchen, you’ve got a third choice: send the show to that TV at the same time.
All you need is an HDMI splitter (assuming that your source — DVD player, DVR, or set top box — has HDMI connectors) that will let you connect two TVs to the same source. Then you can stay current with the show as you go back and forth to raid the refrigerator. And the single cable will carry the sound as well as the video image. Note that you can run long cables for HDMI connections, though you may need to invest in a high quality cable or additional hardware if you go farther than 20 to 30 feet.