kindly define what you mean by "ground level up".
Meaning you shoot vertically upwards toward the sky?
as already suggested, I suppose for either of the 2 scenarios:
a) aiming the camera straight upward and not wanting to strain the neck leaning backwards.
b) aiming horizontal but very close to the ground
an angle finder or use of LiveView (with articulating LCD, lagi better ) would probably satisfy your requirement.
i think you can look under Mass Sales to find an angle finder.
ArtworkFoto.com has this Seagull right angle viewfinder for $85 http://www.artworkfoto.com/others.html. Other mass sellers might have other brands or something. (I quoted ArtworkFoto as they are the first stickied mass seller advertising accessories)