Plane relations for spirals and early-type galaxies, respectively, with typical errors in distance of $\sim 20\%$. However, samples based on distance indicators with significant smaller errors, such as those based on surface brightness fluctuations and nearby Type Ia supernovae, are slowly growing and have already been successfully used to measure $\beta$[@tonry][@riess].

In contrast to the rapid growth of samples with complete redshift information, redshift-distance samples have been difficult to gather. There are various practical reasons for that. First, to ensure the uniformity of the data and of the sky coverage requires coordinated observations in both hemispheres. Second, TF distances require the measurement of the rotational velocity of the galaxy either from the HI line width, which can only be efficiently measured in the northern hemisphere, or from measurements of optical rotation curves, a challenging observation. Third, for early-type galaxies, high signal-to-noise spectra are required for accurate measurements of the velocity dispersion. Finally, both distance indicators require high-quality photometric data. Table \[rd\] summarizes the redshift-distance surveys conducted to date. The table includes only wide-angle redshift-distance surveys and the number of objects is just indicative of the sample size. Not included are the various surveys conducted to measure distances and peculiar velocities 