Disks not in a zpool

Ever wish you had a simple one-liner to tell you which of your /dev/rdsk's weren't in a zpool? Well now you do...

    diff <(zpool status | awk '/c.t.d./ {print $1}' | sort) <(ls /dev/rdsk/c?t?d? | cut -f4 -d/ | sort) | awk '/^>/ {print "free disk: " $2}'