XKCD: Depth Perception Enhancer (can someone make this app)
xkcd.com
xkcd.com
Also, Cassidy Curtis is a rather interesting person: http://www.otherthings.com/uw/
Oh, and I call this prior art so no numb-nutz can go try to patent it.
Wouldn't the orientation of the cameras need to be precise? I suppose you could correct for that in software...
Which results in about 300ft or a football field. The you make that distance, the less the clouds will feel like tangible objects.