ZFS boot saves the day...
I installed Solaris
on my laptop a short while ago. Being my usual goofy
self I was playing around as root in places I shouldn't have been
and managed to really mess things up and render my machine totally
unbootable. It was nosediving within a small fraction of a second
after booting... I only had one kernel image, and that file had
been overwritten :-( Ending up in an infinite reboot loop. In past
days, with either Linux or Solaris, I'd have reinstalled the
system, possibly preceded by ripping the disk out and plugging it
into another machine so that I could rescue any important files.
But since 2008.05 uses ZFS for everything - even the root
filesystem, all I had to do was boot the 2008.05 LiveCD, zfs
the root filesystem, and like magic all my screwing
around was undone.