I found some ready-made code to draw spheres and lines on them in this paper, which refers to this example.
Bottom line is that I do not get the presented result using MiKTeX on 64-bit Windows 7, using either the LaTeX->dvi->ps->pdf chain or direct PDFLaTeX.
These are the results of the example code in the second link on my system:


Everything seems fine except the latitude and longitude lines. How can I solve this?