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ABSTRACT. We review seven of the most reliable techniques used for
deriving distances to galaxies as far away as 100 Mpc: globular cluster
luminosity functions (GCLF), novae, Type Ia supernovae (SN Ia),
HI-line width relations, planetary nebula luminosity functions (PNLF),
surface brightness fluctuations (SBF),
and fundamental plane relationships for elliptical galaxies
(Dn -
). In addition, we examine the
use of Cepheid variables since
these serve to set zero points for most of the methods. We pay
particular attention to the uncertainties inherent in these methods,
both internal and external. We then test these uncertainties by comparing
distances derived with each technique to distances derived from surface
brightness fluctuations. We find that there are small systematic offsets
between the PNLF, GCLF, and SBF methods, with the PNLF and GCLF distances
being on average 6% and 13% larger than those of the SBF method. The
dispersion between the PNLF and SBF distances is 8%; the GCLF-SBF
dispersion is 16%, the SN Ia-SBF dispersion is 28%, the
Dn-
-SBF
dispersion is 26%, and the Tully-Fisher-SBF dispersion
is 32%. The latter value drops to 14%, however, when one considers
only well mixed groups, suggesting that the spiral galaxies measured with
Tully-Fisher are not always spatially coincident with the groups'
elliptical galaxies. In the mean, all the methods agree extremely well.
We also present a summary of distances to the Virgo Cluster. Weighted
and unweighted averages of the 7 methods yield Virgo distances of 16.0
± 1.7 and 17.6 ± 2.2 Mpc, respectively. The overlap among all
the indicators is well within the expected accuracies of the methods,
thus removing any evidence for a distance scale controversy. Using the
weighted or unweighted Virgo distances to bootstrap to the Coma
Cluster, we find the Hubble constant to be either 80 ± 11 or 73
± 11 km s-1 Mpc-1, respectively.