With a little adaption: 
perl -le '@w=grep{length()>5&&length()<8&&/^[a-z]+$/}<>;chomp@w;print 
+join" ",map{$w[rand@w]}1..4'</usr/share/dict/words

[download]
Some samples: 
octyl forrad ruble smoked
unlit stamp finish stumpy
baring pattu helium place
tiptop sundri alumni anilla
dodge blout spurl fasher
lownly setal untar nuchal

[download]
There are 23560 entries in my /usr/share/dict/words that match, giving 308106701416960000 different potential pass phrases. If an attacker can test 1 billion pass phrases per second, it takes almost 10 years to check the entire key space.

I consider that secure enough for my Perlmonks password.

In reply to Re: xkcd-style password generation by JavaFan
in thread xkcd-style password generation by Tanktalus

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