We have nearly completed a large survey of galaxy distances using the SBF method. The first paper on the calibration, zero point, and Hubble constant has been accepted for publication in the ApJ. Subsequent articles will address a detailed description of our analysis method, the dynamics of the Virgo supercluster, the Centaurus supercluster and Great Attractor region, the distance data for the entire survey, the photometry, and finally the images themselves will be made available.
Beyond this work we foresee that K band SBF will become more important as detectors improve. As new, large telescopes come on line which are optimized for near-diffraction limited performance in the IR, such as Gemini and the VLT, SBF will be a valuable tool for extragalactic studies.
Likewise, the Hubble Space Telescope already is a fantastically powerful facility for measuring SBF, and can easily reach past 10,000 km s-1. Lauer et al. have a proposal in Cycle 5 to calibrate BCGs and derive H0 from the BCG Hubble diagram. We have a proposal in Cycle 6 to chart the flow around the Great Attractor. In Cycle 7 NICMOS will fly, and it will be much more powerful than its ground-based counterparts, not only because the psf is smaller and more constant, but mainly because the sky background is so much fainter. Further still in the future, the Advanced Camera is expected to use SBF to probe large scale flows out to 10,000 km s-1.
Although this work has stressed the use of SBF for determining distances, it is also a new handle on stellar populations. Particularly at blue and IR wavelengths, an SBF observation gives us a look at the giant branch which is complementary to the standard observations of color and line strength, and can help disentangle the effects of age and metallicity.
As a distance estimator, SBF will be useful for 1 < d < 200 Mpc, and as the theoretical models and observations of nearby stellar populations improve, SBF will be thought of as a secondary or even primary distance estimator. Right now, H0 = 80 km s-1 Mpc-1 looks like a good bet. If H0 = 60 km s-1 Mpc-1 or the distance to Fornax is greater than 20 Mpc, then there must be something very wrong with SBF, but as yet the indications are very promising for the future usefulness of SBF.