Deejay chimes in this week on DSLR Film Noob with a couple of great videos featuring an awesome find on eBay. It's a little "rear view" monitor intended for cars with cameras implanted in the back somewhere. But hey, a monitor is a monitor and as long as there is a video input and a way to power it, you can used it for any video application.
Deejay comes up with nifty use for this tiny $23 screen, which is to create an articulating monitor for his Canon t2i, which has a fixed LCD. If you have built (or are thinking of building) the Frugal Crane / Jib, this is another great way to check framing and composition when you can't see your camera's flip out screen.
Be sure you check out Deejay's site for more complete information on where to get the monitor and how to to attach it to your rig.