  It is notoriously difficult to measure the winds of solar-type stars.
Traditional spectroscopic and radio continuum techniques are sensitive to mass
loss rates at least two to three orders of magnitude stronger than the Sun's
relatively feeble wind. Much has been done with these methods to probe the more
massive outflows of younger (T Tauri) and older (giant, AGB, supergiant) cool
stars, but the main sequence remains terra incognita. This presentation reviews
the limits on traditional diagnostics and outlines more recent ideas such as
Lyman alpha astrospheres and charge-exchange X-ray emission. In addition, there
are hybrid constraints on mass loss rates that combine existing observables and
theoretical models. The Sackmann/Boothroyd conjecture of a more massive young
Sun (and thus a much stronger ZAMS wind) is one such idea that needs to be
tested further. Another set of ideas involves a strong proposed coupling
between coronal heating and stellar mass loss rates, where the former is easier
to measure in stars down to solar-like values. The combined modeling of stellar
coronae and stellar winds is developing rapidly, and it seems to be approaching
a level of development where the only remaining ``free parameters'' involve the
sub-photospheric convection. This talk will also summarize these theoretical
efforts to predict the properties of solar-type main-sequence winds.
