Originally posted by: TommyVercetti
Isn't that almost the same thing as having an LCD display that tilts, flops, rotates etc?
Except that you can't get one on a DSLR (yet).
I actually did something like this with a pinhole video camera and a small LCD screen, same concept.
It's only really useful for making sure you have the subject in the viewfinder, I found that even with autofocus on it was just too hard to aim. It can come in handy but as other people have said, it is limited.