  We report the observation of features near 1 keV in the ASCA spectra from
three ``Narrow Line Seyfert 1'' (NLS1) galaxies. We interpret these as oxygen
absorption in a highly relativistic outflow. If interpreted as absorption
edges, the implied velocities are 0.2--0.3c, near the limit predicted by
``line-locking'' radiative acceleration. If instead interpreted as broad
absorption lines, the implied velocities are ~0.57c, interestingly near the
velocity of particles in the last stable orbit around a Kerr black hole,
although a physical interpretation of this is not obvious. The features are
reminiscent of the UV absorption lines seen in broad absorption line quasars
(BALQSOs), but with larger velocities, and we note the remarkable similarities
in the optical emission line and broad band properties of NLS1s and
low-ionization BALQSOs.
