Hmm. Now that I think about it, I'm not sure that I ever responded on this subject.

Anyway, here's the settings I'm currently using to generate passwords that I think are very xkcd-like:

my $config = {
dictionary_file => 'sample_dict.txt',
min_word_length => 4,
max_word_length => 8,
};

$config->{num_words} = 4;
$config->{case_transform} = 'NONE';
$config->{custom_separator} = '-';
$config->{prepend_numbers} = 0;
$config->{append_numbers} = 0;
$config->{pad_char} = '-';
$config->{pre_pad} = 0;
$config->{post_pad} = 0;
$config->{random_source} = 'PERL';

True xckd-like passwords would use the space character as a separator, so that you can get "correct battery horse staple" instead of "correct-battery-horse-staple", but for my purposes I think that the dash character works better as a word separator.

I've also taken words from the diceware password generator and a few other sources to help improve the size and quality of my dictionary, but only because I wanted to make sure that I could get to 10k words.