I am fairly new with SolidWorks, but found myself in a situation where I am trying to create a smooth sided rectangular box with C2 curvature everywhere. All the faces are domed, so there are no flat edges, and the edges blend faces smoothly. The concept is very similar to the surfacing challenge: Puffy Box found at http://www.dezignstuff.com/blog/?p=1490 except that all the edges smoothly blend each face. Any suggestions would be greatly appreciated.

Can you create a block and then apply fillets (using the curvature-continuous option, instead of tangent option)? If not, is it really a box, or is it some other form of oblong shape? (In other words, are there any planar surfaces remaining at all or not?)