I got this:

^C410165+0 records in
410165+0 records out
210004480 bytes transferred in 56.621826 secs (3708896 bytes/sec)
Macintosh:~ myname$ sudo dd if=/dev/rdisk0 of=/dev/null conv=noerror
sudo: /var/db/sudo writable by non-owner (040707), should be mode 0700