So far as I know, Word does not have a predefined keystroke or command for
this, but someone tell me if I am wrong.

You can define a style that will single-space, indent, and add space before
and after to keep spacing even within a double-spaced text, and assign it a
keystroke so you can apply it easily to the selected text.

Word has a Block Text style which might be intended to enable this function,
but the formatting is not right for my needs.

Use Format | Style (New, or Modify Block Text) to define the style.  The six
drop down fields under Format... have all the options.  Be sure to check Add
to Template, but NOT Automatically update.  I found after playing with it
that putting 12pt space after made the block quotation come out right when I
double-spaced the rest of the paper.

Use Tools | Customize, Keyboard....to set a shortcut key for your chosen
style.

In this case, when you double space the paper, instead of selecting all and
manually formatting it as double-space, go back to the Format | Style dialog
and redefine the Normal style as doublespaced (or whatever style your main
text is in).  

Hope that helps,
DM

On 9/8/03 4:15 PM, in article 453501c37645$ebe74890$a001280a@phx.gbl,

Hi, Philip,

Assign a paragraph style to the text, having left and right indents of the
proper size. You can use the built-in style "Block Text", which has 1-inch
left and right indents, or you can modify that style or define a new style
with your preferred name and indents.