Release your inner artist with this potter's wheel Demonstration. Make any shape you want using the profile curve editor and then see how it looks revolved in 3D.
The surface of revolution uses NURBS circle control points that can be found in L. Piegl, W. Tiller, The NURBS Book, New York: Springer, 1997 pp. 298–310. This generates perfect circles of revolution, unlike the Bézier approximation of a circle.