ACPI administration advocacy advocacy advocacy opinion alsa apache apple apt aptitude audio authentication awk bash BIOS boot business cache calendar censorship commandline cron database debian desktop development disk dvd economics emacs email europe exim files firefox firewall flash foss freedom ftp fun git grub hardware hardware html images installation ipod kde kernel keyboard knoppix laptop latex linux locale lockin longlines microsoft minitab mplayer multimedia mysql network nfs openbox openoffice opinion opinion partition pdf perl php politics postgresql printing privacy rant rxvt script scripting scsi security sed server shell siteadmin sitenews sitesoftware skype skype slackware sound spam ssh statistics subversion sudo svk swap t23 t43 terminal text thinkpad thunderbird time timezone ubuntu upgrade users versioncontrol video windows wine wordpress wordprocessing X40 xwindows xwindows youtube
In the world's best text editor, the traditional way (as far as I'm concerned, at least) of getting paragraphs of plain text to wrap is to use autofill-mode. That's what I'd been doing.
This mode has a problem in that it inserts a hard break at the end of each line. This wouldn't be a problem except when you are interacting with the non-Emacs world and with such productivity applications as web browsers, email programmes, word processors and so on.
To fix this, the solution is to use longlines-mode. This mode makes it look as if your text has a linefeed inserted at the end of the line, but in fact, when you save the file or copy it anywhere, that linefeed disappears.
To do this, I commented out the line that turned on auto-fill:
(add-hook 'text-mode-hook 'turn-on-auto-fill)
and turn on longlines mode:
(add-hook 'text-mode-hook 'longlines-mode)
Hopefully, that should do the trick. More info.
Red Hat Certified Technician & Engineer (RHCT and RHCE) Training Guide and Administrator's Reference