when my machine is in trouble, i usually do not have a window where
	i log on as root, so i can do very limited troubleshooting (for
	instance, i cannot change shlib symlink to older one as "itojun").

	so - how about adding "su" in rescue binary?  there may be file
	size issue (due to addition of password check routine).  or, if
	we make "su" runnable by people in wheel group, we can skip password
	check? (leaving a room with logged-in terminal has always risk so
	it just increases risk factor)

itojun