NOTE: In order for this to work with newer versions of ssh, you must  
insure that "HashKnownHosts" is set to "no".

This is what I would call overkill, but it should help illustrate
what some people like to do with ssh completion.
----------

zstyle ':completion:*' format 'Completing %d'
zstyle ':completion:*' group-name ''

zstyle ':completion:*:scp:*' tag-order \
	'hosts:-host hosts:-domain:domain hosts:-ipaddr:IP\ address *'
zstyle ':completion:*:scp:*' group-order \
	users files all-files hosts-domain hosts-host hosts-ipaddr
zstyle ':completion:*:ssh:*' tag-order \
	users 'hosts:-host hosts:-domain:domain hosts:-ipaddr:IP\ address *'
zstyle ':completion:*:ssh:*' group-order \
	hosts-domain hosts-host users hosts-ipaddr

zstyle ':completion:*:(ssh|scp):*:hosts-host' ignored-patterns \
	'*.*' loopback localhost
zstyle ':completion:*:(ssh|scp):*:hosts-domain' ignored-patterns \
	'<->.<->.<->.<->' '^*.*' '*@*'
zstyle ':completion:*:(ssh|scp):*:hosts-ipaddr' ignored-patterns \
	'^<->.<->.<->.<->' '127.0.0.<->'
zstyle ':completion:*:(ssh|scp):*:users' ignored-patterns \
	adm bin daemon halt lp named shutdown sync

zstyle -e ':completion:*:(ssh|scp):*' hosts 'reply=(
	${=${${(f)"$(cat {/etc/ssh_,~/.ssh/known_}hosts(|2)(N) \
			/dev/null)"}%%[# ]*}//,/ }
	${=${(f)"$(cat /etc/hosts(|)(N) <<(ypcat hosts 2>/dev/null))"}%%\#*}
	)'

zstyle ':completion:*:(ssh|scp):*:my-accounts' users-hosts \
	my.secret.account@student.uu.se