Yep, "correct horse battery staple" is a very good password, and everyone should use that everywhere ;-)

But seriously, I have a GIST for that <https://gist.github.com/cbbrowne/1201859>

root@cbbrowne:/tmp#  echo $(grep "^[^'A-Z]\{3,7\}$" /usr/share/dict/words|shuf -n4)
dressed sliders replace padded
root@cbbrowne:/tmp#  echo $(grep "^[^'A-Z]\{3,7\}$" /usr/share/dict/words|shuf -n4)
khan tailor con junky
root@cbbrowne:/tmp#  echo $(grep "^[^'A-Z]\{3,7\}$" /usr/share/dict/words|shuf -n4)
ritual prince ethics brags
root@cbbrowne:/tmp#  echo $(grep "^[^'A-Z]\{3,7\}$" /usr/share/dict/words|shuf -n4)
guava facet rumbas drape
root@cbbrowne:/tmp#

It's common for password policies to include (capitalize something, have a digit, have a non-alphanumeric character); it would be easy to augment with a random digit and a random choice of some special chars.  I haven't bothered doing any code for that ;-)