I've seen a wine bottle and a toaster done before. I think a monitor would be cool, get a crt, and put a lcd inside, kinda like an imac, but better (because it runs windows and linux natively, and doesn't look ugly as ass)
But wouldn't the updated version of your idea look exactly like an iMac or a Gateway One?
Or get some 6.5'' mini screens and install two of them on the top of the case. That would be awesome. Impractical, but awesome.
now that would be cool! Not that usefull, though I guess you could have like a temp monitor program or something similar on those screens.
But who cares about usefull anyway, I'd love to have a case like that!