  Multi-wavelength observations of nearby spiral galaxies have shown that
neutral and ionized gas are present up to a few kpc from the disk and that star
formation and supernovae probably play an important role in bringing gas into
the halo. We have obtained very sensitive HI observations of the face-on galaxy
NGC 6946 and of the nearly edge-on starburst galaxy NGC 253. We find high
velocity HI clouds in NGC 6946 and extra-planar gas with anomalous velocities
in NGC 253. In both galaxies there seems to be a close connection between the
star-forming disk and the halo HI. In the outer parts of NGC 6946 there is also
evidence for recent gas accretion.
