The Zigview S2 Digital Angle Finder is a detachable high-rez 2.5-inch viewfinder that clamps onto your digital SLR's eyepiece, and you can either use it as a waist-level finder or take it off the camera and still get a good view of your shot even if your camera is in one of those high- or low-angle situations.
Plus, there's a TV output for viewing on a remote monitor, and a remote video accessory that includes cables and extensions that let you snap those shots from up to 30 feet away. So now you can park that camera up a tree next to a bird's nest, keeping an eye on your viewfinder while you stay safely on the ground. You'd better be pretty serious about this, because it costs $467.
Zigview S2 Digital Angle Finder [PhotographyBlog]