Thanks
luli82 for recommending Google SketchUp! I just downloaded the demo and after watching a brief video tutorial was able to create a scale 3D rendering of the lower lobby of the Boeing IMAX theater. Google is so genius at making intuitively useful software. I should be able to construct floor plans and elevations for the space, which has curved walls without any trouble! sweeeeeeeeet!
The measurements aren't exact, because I was trying to trace directly over a schematic that was scaled at 10' = 1" with no dimensions given. Still, I think its pretty good work for 1 hour's time.