  We present an analytical model for the magnetic flux surfaces for rapidly
rotating magnetized young stellar objects which is based on ideal, stationary,
axisymmetric magnetohydrodynamics. The resulting cold wind solutions reproduce
observed wind velocities of a few hundred \kms$ $ and the outer jet radi us for
a collimated jet of several thousand stellar radii. The theory of axisymmetric
magnetospheres around rapidly rotating stellar sources is outlined including
electric fields due to the rapid rotation. Gravity of the central object is
consistently built into this theory. A consistent wind theory is developed
which contains the Newtonian theory as a classical limit. Current--carrying
plasma flows will lead to a collimation of the magnetospheric structure into a
cylindrical shape. We show that the asymptotic structure is essentially
determined by electric forces in the pinch equation, and not by centrifugal and
pressure forces.
