  The powerful narrow jets observed to emanate from many compact accreting
objects may arise from the twisting of a magnetic field threading a
differentially rotating accretion disk which acts to magnetically extract
angular momentum and energy from the disk. Two main regimes have been
discussed, {\it hydromagnetic outflows}, which have a significant mass flux and
have energy and angular momentum carried by both the matter and the
electromagnetic field and, Poynting outflows, where the mass flux is negligible
and energy and angular momentum are carried predominantly by the
electromagnetic field. Here we consider a Keplerian disk initially threaded by
a dipole-like magnetic field and we present solutions of the force-free
Grad-Shafranov equation for the coronal plasma. We find solutions with Poynting
jets where there is a continuous outflow of energy and toroidal magnetic flux
from the disk into the external space. This behavior contradicts the commonly
accepted ``theorem'' of Solar plasma physics that the motion of the footpoints
of a magnetic loop structure leads to a stationary magnetic field configuration
with zero power and flux outflows.
  In addition we discuss recent magnetohydrodynamic (MHD) simulations which
establish that quasi-stationary collimated Poynting jets similar to our
Grad-Shafranov solutions arise from the inner part of a disk threaded by a
dipole-like magnetic field. At the same time we find that there is a steady
uncollimated hydromagnetic outflow from the outer part of the disk. The
Poynting jets represent a likely model for the jets from active galactic
nuclei, microquasars, and gamma ray burst sources.
