Most high-definition televisions have a "Picture-in-Picture" feature that is useless; if you are watching a HD input the PIP window can only display a low-resolution input such as RF or Composite SDTV. Furthermore the sole Composite video input is often combined with the Component video input which may already be used by your older video game console.
What's left? I'll show you how to use your HDTV's coaxial cable TV RF input to view up to four network security cameras in the PIP window so you can keep an eye on your perimeter while watching something else.