  Type Ia supernovae are the best cosmological standard candles available. The
intrinsic scatter of their decline-rate- and colour-corrected peak brightnesses
in the Hubble diagram is within observational error limits, corresponding to an
uncertainty of only 3km/s/Mpc of the Hubble constant. Any additional
uncertainty, resulting from peak-brightness calibration, must be kept small by
measuring distances to nearby host galaxies most precisely.
  A number of different distance determinations of the Fornax cluster of
galaxies agree well on a distance modulus of 31.35+-0.04mag (18.6+-0.3Mpc).
This leads to accurate absolute magnitudes of the well-observed Fornax type Ia
SNe SN1980N, SN1981D, and SN1992A and finally to a Hubble constant of
H_0=72+-6km/s/Mpc.
