Please don't take this the wrong way, but I think the problem is that someone is taking the t.v. show way too literally. Just because they show a technology on t.v. doesn't mean it's real technology that's currently available. As a theatre major, I know a few ways to fake what they're showing on NCIS.

That being said, you'd need a video switcher if you wanted to use multiple computers to possibly input to the t.v. screen. And if wireless isn't available for this, you'd need a wired switch.

I'm thinking you'd need something ala Apple TV, if that helps your google-fu.