What you need:

Xbox360/PS3/Wii

Video Camera with an av cable.

Xbox360/PS3/Wii standard Av Cable (No HD cable).

Camera (Any video camera) with an av output.

3 RCA Y Splitters (Optional if your TV has an av out).

Tutorial:

1. Plug in the y splitters into the Video and Right and Left Audio jacks. (it doesn't matter where they get plugged into)

2. After you did that plug in the standard xbox360/PS3/wii video and audio jack.

3. Plug in your cameras av jack in to the video and audio jack as well.

4. Plug your cameras av into your Camera if you didn't already did so.

5. On your camera on "AV IN"

6. Turn your Xbox360/PS3/Wii on and Enjoy!