  Electro-optical feedback has many features in common with optical
nonlinearities and hence is relevant to the generation of squeezing. First, I
discuss theoretical and experimental results for traveling-wave feedback,
emphasizing how the ``in-loop'' squeezing (also known as ``squashing'') differs
from free squeezing. Although such feedback, based on ordinary (demolition)
photodetection cannot create free squeezing, it can be used to manipulate it.
Then I treat feedback based on nonlinear quantum optical measurements (of which
non-demolition measurements are one example). These {\em are} able to produce
free squeezing, as shown in a number of experiments. Following that I discuss
theories showing that intracavity squeezing can be increased using ordinary
feedback, and produced using QND-based feedback. Finally, I return to
``squashed'' fields and present recent results showing that the reduced in-loop
fluctuations can suppress atomic decay in a manner analogous to the effect for
squeezed fields.
