ORIGINAL: Gringo Volador
Styrofoam ice chests make great super cheap airplane stands. Use the base and then just cut out the shape of the fuselage. They don't damage the plane and are great for working with while the plane is upside down.
This is what I do. I also use the same box when I transport my smaller planes to the flying field, as the box also makes for an excellent storage for the parts and tools that are specific to that plane.
Good tip Gringo Volador