herbert,
> see http://mirror.ctan.org/graphics/pstricks/contrib/pst-
> electricfield/
I tried it, but it looks not the right way in case of not equally
large charges:
\psElectricfield[%
10 Q={[-1 3 0][2 3 0]},linecolor=red,posArrow=0,points=2000,Pas=0.025]
??? the lines leaving the charges are not equidistant
d