RE: What if sometimes want auto-filling and sometimes don't?Necessary to keep manually turning on/off?

[Drew Adams]

> When I want to join a paragraph of lines together I use M-^ which is
> confusingly named delete-indentation, although the key character
> mnemonic is perfect.
> 
> I put the point on the last line and then hold down the META and SHIFT
> keys and press ^ once for each line and join what I want up into one
> line.

+1 for the usefulness of `M-^'; I use it a lot.

I particularly like the fact that it moves point to the join position, so you
can insert stuff there.

Even if I just want to insert a comment at the end of the previous line, it can
be quicker to use `M-^ M-; My comment C-j' than to use, say, `C-e C-p C-e M-; My
comment' (depending on where I want to end up).

[I also have `C-a' and `C-e' bound to repeatable bol/eol movements, so pressing
and holding `C-a' tracks up bols and `C-e' tracks down eols.  For instance, `C-a
C-a C-e' also takes me to the end of the previous line.  As a result I probably
use `C-a' and `C-e' a bit more, and `M-p' and `M-n' a bit less, than other users
do.

C-a/C-e as repeatable commands `(beginning|end)-of-line+' are here:
http://www.emacswiki.org/emacs-en/download/misc-cmds.el]