I would love there to be some kind of hacker's hardware gadget that allowed people to take various panels and connect them to computers.

While you're talking about big high res panels, I'd be happy with an extra little low res panel; any of the Nintendo DS screens, for example. But being able to use these old little panels could prevent some of them ending up in landfill.

I guess the other problem is the weirdly sub-optimal nature of multiple monitors - despite years of people wanting to use multiple monitors it's still a bit kludgy.