Abstract
The detection of UV absorption, 21 cm, Hα and other diffuse optical emission lines from gas up to ten kiloparsecs above the plane of the Milky Way and other galaxies provides the first opportunity to probe the rotational properties of the ionized ``atmospheres'' of galaxies. This rotation has implications for our understanding of the Galactic gravitational potential, angular momentum transport in the Galactic disk, and the maintenance of a Galactic dynamo. The available evidence indicates that gas rotates nearly cylindrically up to a few kiloparsecs. This is in contrast to the expectation that there should be a significant gradient in rotation speed as a function of height assuming a reasonable mass model for the Galaxy. For example, for a vertical cut at galactocentric radius R= 5 kpc in NGC 891 by Rand, the rotation speed is observed to drop by ~ 30 km s-1 from z=1 to 5 kpc and is expected to drop by 80 km s-1. Magnetic tension forces may resolve this discrepancy. Other possiblilities will be examined in the near future.